A "subject complement" is a word or a group of words that appears in the PREDICATE part of the sentence BUT refers to or describes the SUBJECT. "B" is the correct answer, because "better" describes the subject "I," even though it appears AFTER the verb "felt," which means it is in the predicate part of the sentence. Hope this helps!!
I do believe the answer is C) American Civil War.
It hasn't changed anything much. I just can't go to public places and I do online schooling.
Joy is probably the best synonym for this word.
Hope this helps!