7515. COMBAT

✅ The correct answer is option D.
Conflict : a serious disagreement or argument, typically a protracted one.

Quarrel : a heated argument or disagreement, typically about a trivial issue and between people who are usually on good term.

Feud : a prolonged and bitter quarrel or dispute.

Fight : take part in a violent struggle involving the exchange of physical blows or the use of weapons.

Combat : fighting between armed forces.

Synonym of Combat is Fight