Juan Trippe, the founder of Pan American Airways, because he planned

OFFICIAL EXPLANATION

C

This is a tricky sentence to fix because it includes two pieces of background information about Trippe. There's only room for one between a pair of commas (such as "the founder of Pan American Airways") so the correct sentence will find a way to include both without the ambiguity of the initial sentence.

Eliminate (A) because you can't "read around" the first phrase: "Juan Trippe because he planned. . . " doesn't make sense.

(B) is incorrect because of its use of the passive voice, "was planned by". Also, the "and" in "and so he" is unnecessary; "so he" would be sufficient.

(C) is correct: it moves one of the pieces of background information to a modifier. It is Trippe who planned to expand his airline's service; he was also the founder of the airline, and if you read around the "the founder" phrase, the sentence works: "Trippe acquired several. . . "

(D) has a modifier problem and incorrect parallelism. It is Trippe who was "planning to expand", not "Airways", which immediately precedes the verb. Also, by preceding "acquired" with "and", it sounds like there should be a past tense verb somewhere earlier in the sentence. There is not.

(E) moves the phrase "the founder. . ." too far away from what it modifies, "Juan Trippe". The modifier must be immediately adjacent to what it modifies.