Critical Reasoning

1) Determining the authenticity of purported pre-Columbian artifacts is never easy. Carbon-14 dating of these artifacts is often impossible due to contamination by radioactive palladium (which occurs naturally in the soils of Central and South America). However, historians and anthropologists have evolved two reliable criteria, which, utilized in combination, have proven effective for dating these artifacts. First, because authentic pre-Columbian artifacts characteristically occur in a coarse, granular matrix that is shifted by major earthquakes, they often exhibit the unique scratch patterns known as gridding. In addition, true pre-Columbian artifacts show a darkening in surface color that is caused by centuries of exposure to the minute amounts of magnesium in the soil of the Americas.

The criteria above would be LEAST useful in judging the authenticity of which of the following?
(A) An ax head of black obsidian, unearthed from a kitchen midden
(B) A pottery bowl with a red ocher design, found in the ruins of a temple
(C) A set of gold ear weights, ornamented with jasper pendants
(D) A black feather cape from a king's burial vault
(E) A multicolored woven sash found near the gravesite of a slave

OA is D. Is it because the feather won't be able to last as a fossil? Frankly i didn't understand the other options and their relevance with the passage. Kindly explain


Questions 2-3 are based on the following.

From time to time, the press indulges in outbursts of indignation over the use of false or misleading information by the U.S. government in support of its policies and programs. No one endorses needless deception. But consider this historical analogy. It is known that Christopher Columbus, on his first voyage to the New World, deliberately falsified the log to show a shorter sailing distance for each day out than the ships had actually traveled. In this way, Columbus was able to convince his skeptical sailors that they had not sailed past the point at which they expected to find the shores of India. Without this deception, Columbus's sailors might well have mutinied, and the New World might never have been discovered.
2) The author of the passage above assumes each of the following EXCEPT:
(A) Government deception of the press is often motivated by worthy objectives.
(B) Without government deception, popular support for worthwhile government policies and programs might well fade.
(C) Attacks on the government by the press are often politically motivated.
(D) Deception for deception's sake should not be condoned.
(E) A greater good may sometimes require acceptance of a lesser evil.

OA is C but I had marked A.


3) Which of the following is the main weakness of the historical analogy drawn in the passage above?
(A) The sailors in Columbus's crew never knew that they had been deceived, while government deception is generally uncovered by the press.
(B) A ship's log is a record intended mainly for use by the captain, while press reports are generally disseminated for use by the public at large.
(C) The members of a ship's crew are selected by the captain of the ship, while those who work in the press are self-selected.
(D) The crew of a ship is responsible for the success of a voyage, while the press is not responsible for the use others make of the factual information it publishes.
(E) In a democracy, the people are expected to participate in the nation's political decision making, while the members of a ship's crew are expected simply to obey the orders of the captain.

My answer was A but the OA is E.



4) Which of the following best completes the passage below?
Monarch butterflies, whose average life span is nine months, migrate from the midwestern United States to selected forests outside Mexico City. It takes at least three generations of monarchs to make the journey, so the great-great-grandchildren who finally arrive in the Mexican forests have never been there before. Yet they return to the same trees their forebears left. Scientists theorize that monarchs, like homing pigeons, map their routes according to the earth's electromagnetic fields. As a first step in testing this theory, lepidopterists plan to install a low-voltage transmitter inside one grove of "butterfly trees" in the Mexican forests. If the butterflies are either especially attracted to the grove with the transmitter or especially repelled by it, lepidopterists will have evidence that______
(A) monarch butterflies have brains, however minuscule
(B) monarch butterflies are sensitive to electricity
(C) low-voltage electricity can affect butterflies, whether positively or adversely
(D) monarchs map their routes according to the earth's electromagnetic fields
(E) monarchs communicate in intergenerationally via electromagnetic fields

What is the difference between B (OA) and C?