The soldier provided his mettle in the battlefield.

Answer: Option C

persistence : the fact of continuing in an opinion or course of action in spite of difficulty or opposition.
stamina : the ability to sustain prolonged physical or mental effort.
courage : the ability to do something that frightens one; bravery.
heroism : great bravery.
mettle : a person's ability to cope well with difficulties.

Synonym of mettle is courage