The "iliad" and the "odyssey" are important because they a. tell the true history of the trojan war b. are great works of literature that us c. understand life in ancient greece d. present factual accounts of the beginnings of greek civilization are factual accounts of the persian invasion of greece

I think the options are confusing, here they are, re-edited.

A. tell the true history of the Trojan War
(this is not necessarily true, so not this option)

 B. are great works of literature that help us  understand life in ancient Greece
- yes! this is the correct answer. There are very old texts and they give us an insight into the past.

C. present factual accounts of the beginnings of Greek civilization
(we don't know whether that's true)

D. are factual accounts of the Persian invasion of Greece
(no, not the correct answer).