The answer is C: Personification because the sun is given human-like qualities ("slumber"). It can't be A because a simile compares two things using "like" or "as". It can't be B because imagery refers to the senses. The sentence isn't very.. descriptive. It can't be E because nothing is being exaggerated in any way. I'll be completely honest and say that I haven't learned about synecdoche yet, haha.
B is the only answer choice that gives the reader information rather than an opinion. Answer choices A, C, and D all present opinions, not information.
“in an attempt to save the Chicago Tribune building, men stayed in the roof for as long as possible during the fire, keeping it wet and stamping out cinders.”