Lewis and Clark expedition

Confused bw A and B.

Lewis had been instructed to "explore the Missouri River,by its course and communication with the waters of the Pacific Ocean. . . may offer the most direct and practicable water communication across the continent"

Lewis and Clark observed that the continent was wider than originally supposed.More specifically, they learned a good deal about river drainages and mountain barriers.

From the argument it can be assumed that the trip was concerned with river systems of portions of North America

IMO A

The OA given is C, don't think A and B are too specific to North America? well after reading the answers one might feel so...

but the point is to convert this during the exam!

arora007 wrote:The Lewis and Clark expedition, sponsored by President Jefferson, was the most important official examination of the high plains and the Northwest before the War of 1812. The President's secretary, Captain Meriwether Lewis, had been instructed to "explore the Missouri River, and such principal streams of it as, by its course and communication with the waters of the Pacific Ocean. . . may offer the most direct and practicable water communication across the continent, for the purposes of commerce." Captain William Clark, the younger brother of famed George Rogers Clark, was invited to share the command of the exploring party.

Amid rumors that there were prehistoric mammoths wandering around the unknown region and that somewhere in its wilds was a mountain of rock salt 80 by 45 miles in extent, the two captains set out. The date was May 14,1801. Their point of departure was the mouth of the Wood River, just across the Mississippi from the entrance of the Missouri River. After toiling up the Missouri all summer, the group wintered near the Mandan villages in the center of what is now North Dakota. Resuming their journey in the spring of 1805. The men worked their way along the Missouri to its source and then crossed the mountains of western Montana and Idabo. Picking up a tributary of the Columbia River, they continued westward until they reached the Pacific Ocean, where they stayed until the following spring.

Lewis and Clark brought back much new information, including the knowledge that the continent was wider than originally supposed. More specifically, they learned a good deal about river drainages and mountain barriers. They ended speculation that an easy coast-to-coast route existed via the Missouri-Columbia River systems, and their reports of the climate, the animals and birds, the trees and plants, and the Indians of the West -- though not immediately published -- were made available to scientists.

With what topic is the passage primarily concerned?
(A)The river systems of portions of North America
(B)Certain geological features of the North America
(C)An exploratory trip sponsored by the United States government
(D)The discovery of natural resources in the United States
(E)None of the above.

good one!!

I wasted more than 1 minute in deciding what should I choose. I chose the wrong one between A and C.

And just after seeing the OA, I could easily know why I was wrong. The passage does not talk specifically about rivers, It talks about mountain barriers, Pacific ocean and its connection with the rivers, passage in the end talks about animals, plants and tribes.......................so it seems that the passage is a report of the exploration.

I hope I would not miss such questions in real GMAT.

What we see: a Reading Comprehension main topic question. It asks what the whole passage is about, so the right choice has to cover all three paragraphs.

Step 1. Name the job of each paragraph.
What we see: paragraph 1 says who sponsored the expedition, who led it and what it was told to do. Paragraph 2 follows its route to the Pacific. Paragraph 3 lists what it brought back.
What it means: the three paragraphs are the start, the middle and the result of one trip.
What we do and why: we write "one trip, start to finish" on our scrap paper before reading the choices. A summary in our own words keeps a choice with familiar words from pulling us away.

Step 2. Check the two details in the right choice.
What we see: the passage says the expedition was "sponsored by President Jefferson" and calls it an "official examination." Lewis was told to "explore the Missouri River," and the group is called an "exploring party."
What it means: the passage itself supplies both ideas: a trip made to explore, and government backing.
What we do and why: we match each word in the choice to a line in the passage. That is how we prove a choice instead of just liking it.

Step 3. Test the other choices against all three paragraphs.
What we see:
(A) River systems appear often, but only as the path of the trip.
(B) Geological features come up in a short part of paragraph 3, and the mountain of rock salt is only a rumor.
(D) No paragraph is about finding natural resources. The passage reports new knowledge of land, climate, animals and plants.
(E) "None of the above" works only if no choice fits, and one does.
What it means: each of these fits a detail, but none fits the whole passage.
What we do and why: we drop them, since a main topic answer cannot leave out whole paragraphs.

The trap: (A). Rivers are named again and again, so this choice feels safe. Try this check: the passage opens with the expedition, not with rivers, and paragraph 3 reports climate, animals, plants and people as well. Rivers are one thing the trip used and learned about. They are not the subject.

Faster way: read only the first sentence of each paragraph. All three name the expedition or its two captains, so the topic is clear in about 20 seconds.

Takeaway: a main topic answer must cover every paragraph. A choice that repeats a word you saw many times is often just a detail.

A note on the text: the passage prints the start date as 1801, but the expedition really left in 1804. You can also see the error inside the passage: they wintered once and resumed in the spring of 1805. The date does not change the answer.

Answer: C