What two things are being compared in the simile in the first stanza of "if you were coming in the fall"

In this unit we learned about arguments and rhetoric. in an argument we use ,not informal language

Which of the following is a complex sentence? a. after henry submitted his essay, he realized that he hadn't proofread the last page. b. identity theft is a growing problem, especially among seniors. c. we didn't have enough potatoes for dinner, so we served rice instead. d. jim tried to watch a video on a device connected to a crowded wireless network; as a result, the video stuttered and froze.

Which evidence from the text best supports the idea that malcolm and donalbain believe they need to flee scotland before someone tries to murder them too?