Asubstantiated opinion is best supported by

A substantiated opinion is best supported by expert opinions.  

for me, i'd go with (c) satisfied or (b) overjoyed because if you read it a couple of times, it makes since that it is c or b. it can't b (a) angry because booker was never angry about anything. at the end of the paragraph, booker states, "i think there are not many men in our country who have had the privilege of naming themselves in the way that i " i think that sentence kind of gives away the also, some words in the paragraph can also you like for example, "indulged," "calmly," "perplexity," "privilege," and defining words that you don't know, can you understand more of that paragraph and it can also increase your comprehension. : )

i'm really rally sorry if i'm incorrect, but if i'm hope this ! : )

search it up on google or think from your brain make it work harder.