The adjective clause is, whose branches had died.
and it's modifying the word tree.
Answer for part A:
He uses a metaphor to suggest that white people have proven themselves unworthy of the authority they wield.
Answer for Part B:
It suggests that their deceitful acts are intentional.
I took the test
Rhetorical writing or speech are those that are expressed with the intention to persuade or impress. From the given choices above, the most likely scenario that would use the traditional rhetoric is the classmate who is running for student body president. Thus, the answer is letter B.
I'd have to say C) but I'm not sure.