made of deeds of great valor or requiring superhuman courage.
Options C and D feature parallel structure.
Parallel structure occurs when the same grammatical pattern is used. In options C and D, the same grammatical pattern is used in each: both are questions, and both begin with a verb followed by the subject.
Answer:
Symbols representing fortitude and courage are sacrifice, mental strength, confidence, inner capability, and discipline all play a symbolize these qualities. Hope this helps :)