This question is testing MODIFIERS and COMPARISONS
In July 1965 Mariner IV passed by Mars and took the first-ever close-up photographs of another planet, which showed that the Martian surface was like that of the Moon's in that it was pockmarked by moon like craters and was dry and apparently dead.
a. which showed that the Martian surface was like that of the Moon's in that it was pockmarked by moon like craters and was dry and apparently dead.
b. which showed a dry, apparently dead Martian surface, and it was pockmarked by craters like the Moon has
c. which showed the Martian surface as a dry, apparently dead one, which was pockmarked with craters such as the Moon's
d. photos showing the Martian surface to be like that of the Moon's, dry and apparently dead, and it was pockmarked by moon like craters
e. photos that showed a dry, apparently dead Martian surface pockmarked with craters like those on the Moon
Whenever an underlined portion begins with WHICH, the GMAT is almost certainly testing MODIFIER usage. "Which" is a relative pronoun that must modify the noun (or noun phrase) directly preceding it. This is one of the GMAT's favorite SC issues to test, probably because it is so often misused in spoken English.
Since the logical meaning of the sentence is that the photographs showed new information about the Martian surface, the "which" clause is questionable: it may be modifying "other planets" rather than "photographs." Technically, we can treat [photographs of other planets] as a noun phrase, and a "which" clause could modify it. However, the GMAT is likely to reword the correct answer to avoid the ambiguity issue.
a. which showed that the Martian surface was like that of the Moon's in that it was pockmarked by moon like craters and was dry and apparently dead.
- questionable (though not necessarily incorrect) use of "which" clause
- redundant comparison. We can say "like that of the Moon" or "like the Moon's," but "like that of the Moon's" is redundant.
- "it" is ambiguous
b. which showed a dry, apparently dead Martian surface, and it was pockmarked by craters like the Moon has
- questionable "which" clause
- the "it was" clause is not logically parallel to the preceding clause
- incorrect comparison structure. We can say "craters like the Moon's" or "pockmarked by craters, as the Moon is." The "has" does not belong here.
c. which showed the Martian surface as a dry, apparently dead one, which was pockmarked with craters such as the Moon's
- 2 questionable "which" clauses
- "such as" is used for actual examples, not similarities. This makes it seem like Mars is pockmarked by the Moon's craters - nonsensical!
d. photos showing the Martian surface to be like that of the Moon's, dry and apparently dead, and it was pockmarked by moon like craters
- switching to "photos showing" fixes the modifier issue
- however, there is still a redundant comparison
- the "it was" clause is not logically parallel to any other clause
e. photos that showed a dry, apparently dead Martian surface pockmarked with craters like those on the Moon
- correct! No modifier or comparison issues.
The correct answer is
E.