While the marketing department projected robust sales throughout the summer, typically Allport Corporation's biggest season, the drought in Midwestern states limited total revenue to only $300 million in the third quarter.
(A) typically Allport Corporation's biggest season, the drought in Midwestern states limited total revenue to only
(B) Allport Corporation's biggest typical season, the drought in Midwestern states limited only total revenue to
(C) which typically is Allport Corporation's biggest season, the drought in Midwestern states only limited total revenue to
(D) which is typically Allport Corporation's biggest season, the drought in Midwestern states limiting total revenue to only
(E) Allport Corporation's biggest typical season, the drought in Midwestern states only limiting total revenue to

The most important splits in this SC question concern not grammar but logic. GMAT students sometimes mistakenly think of the GMAT SC as a test of nothing but grammar. In fact, logic & meaning are just as important as grammar, and sometimes incorrect answer choices on SC questions are 100% grammatically correct but logically flawed. For a discussion of Logical Splits on the GMAT SC, as well as the OA & OE of this question, see:
https://magoosh.com/gmat/2014/logical-sp ... orrection/

Mike