Having lived in Tahiti for several years, where life was slow and relaxed, it was difficult for Paul Gauguin to readjust to the hectic pace of Paris upon returning.
OA - Having lived for several years in Tahiti, where life was slow and relaxed, Paul Gauguin had difficulty readjusting to the hectic pace of Paris upon his return.
Original answer is the best choice among all the answer choices but I have one doubt with the usage of had here. I just wanted to confirm that 'had' here is simple past tense and not past perfect, right? I committed the mistake of choosing another answer choice simply because I eliminated this answer choice for using 'had'. Is there a way to determine when 'had' is used for simple past tense and not past perfect tense?