D

i go with the answer option E

Final solution at one place:

Important: The purpose of this post (and all the other posts by me) is to give a complete solution to all GMAT-Prep Verbal questions at one place. Sometimes students have to wade through dozens of posts to get to the final answer. My posts will give one complete and crisp solution required to arrive at the correct answer by eliminating the wrong one. Some of the content in these posts may have been taken from various other sources (discussion forums).

Unlike other Mayan cities, Cancun's commercial power throughout the lowlands seems to be from using its strategic position at the foot of the highlands, which were a source of jade, obsidian, and other valuable commodities.
(A) Cancun's commercial power throughout the lowlands seems to be from using its strategic position at the foot of the highlands, which were a source of jade, obsidian, and other valuable commodities
(B) Cancun's commercial power throughout the lowlands seems to have come from using its strategic position at the foot of the highlands, a source of jade, obsidian, and other valuable commodities
(C) the commercial power of Cancun throughout the lowlands seemed to have come from using its strategic position at the foot of the highlands, a source of jade, obsidian, and other valuable commodities
(D) Cancun seemed to be using its strategic position at the foot of the highlands, which was a source of jade, obsidian, and other valuable commodities, in becoming a commercial power throughout the lowlands
(E) Cancun seems to have used its strategic position at the foot of the highlands, a source of jade, obsidian, and other valuable commodities, to become a commercial power throughout the lowlands

A, B, and C compare 'Mayan cities' to 'commercial power' ... wrong comparison.

D uses a wrong idiom ... 'used ... in becoming'. WRONG! The correct idiom is 'used ... to become'. Also, from the point of meaning clarity, 'seemed to be using' means that someone actually saw Cancun actually using its commercial power in that period, whereas the sentence is clearly designed to say that's the way it seems to us 'now'.

Correct: E

D has 2 problems:
A,B & C out for the obvious reason comparison has to be between the two cities.
D has 2 problems:
1. to become a commercial is preferred over in becoming a commercial
2. which was a source of jade should have been a source of jade; In D use of was is changing the tense

(E)..No gerund

D) ... its strategic position at the foot of the highlands, which WAS a source of jade ...

"which" refers to highlands, so can we eliminate D because it use "was" instead of "were" ?

E for me....

Unlike other Mayan cities, Cancun's commercial power throughout the lowlands seems to be from using its strategic position at the foot of the highlands, which were a source of jade, obsidian, and other valuable commodities.

a. Cancun's commercial power throughout the lowlands seems to be from using its strategic position at the foot of the highlands, which were a source of jade, obsidian, and other valuable commodities

b. Cancun's commercial power throughout the lowlands seems to have come from using its strategic position at the foot of the highlands, a source of jade, obsidian, and other valuable commodities.

c. the commercial power of Cancun's throughout the lowlands seemed to have come from using its strategic position at the foot of the highlands, a source of jade, obsidian, and other valuable commodities.

d. Cancun seemed to be using its strategic position at the foot of the highlands, which was a source of jade, obsidian, and other valuable commodities, in becoming a commercial power throughout the lowlands.

e. Cancun seems to have used its strategic position at the foot of the highlands, a source of jade, obsidian, and other valuable commodities, to become a commercial power throughout the lowlands.

IMO: E

IMO E
A, b, C are out of the race as they compare the commercial power of Cacun with Mayan cities which is wrong.
In option D, (which was a source of)seems wrong. It should be( which were a source of).

Option E is concise and grammatically correct.

A B C Wrong coz of the comparison error. It compares cities with power.

D is wrong coz of the tense. 'Was' is wrong ! Should have been 'were' -> Plural for 'Highlands'

So, Answer is E

Unlike other Mayan cities, Cancun's commerical power.... Right off the bat, there is a paralellism error. You cannot compare cities to commercial power.. they're not the same type of thing. Because "Unlike other Mayan cities" is NOT underlined, we know we are looking for an answer that starts off with a PLACE, namely Cauncun as the subject noun.

We can eliminate A, B, and C.

D- "in becoming" is wordy and awkward... sentence is in past tense but "which was a source" doesn't quite sound right. ""which was" is not necessary either.

E- CORRECT.

As per myvunderstandin e is the correct answer

E in Answer.

usage of "seemed" eliminates C and D.