The roblem with D is that it illogically compares how successful she was in in her emigrated countery to Germany, rather than how successful she was in A to how successful she was in B. Comparisons are a form of parallelism - you have to make sure that you're comparing two things that can logically be compared. Ask yourself - what is being compared here? Are we comparing apples to apples, or apples to turtles?

C corrects this problem by correctly comparing how successful she was after she emigrated to how successful she was in Germany. What makes C hard to swallow is that the first part (up to the first comma) does not have a subject, which makes it sound awkward. It is unclear what the adjective "less successfuly" modifies.

An opening "clause" without a subject is known as a "modifier", or "modifying clause". It is not stand-alone (i.e has no subject and verb), is usually separated by a comma, and must describe the noun directly following that comma. Since the noun after the comma is "Photograppher Lotti Jacobi", C is indeed correct: the adjective "less successful than..." correctly describes Lotti, implying that Lotti was the one less successful after she emigrated than in her native germany.

Following are two simpler example of modifiersalong the same lines (modifier in red):
Running down the street, he slipped and fell
Skilled at at the art of war, The Huns wreaked destruction on eastern europe