The correct answer is B. Fight.
A fight is a physical confrontation between two or more people, usually involving the exchange of blows. It can be a spontaneous event, such as a bar fight, or it can be planned, such as a boxing match.
A quarrel is an angry argument, usually between two people. It can be verbal or physical, but it is not usually as serious as a fight.
A conflict is a disagreement or clash between two or more people or groups. It can be over anything, from a trivial matter to a major issue.
A feud is a long-running quarrel between two families or groups. It is often characterized by violence and hatred.
In the context of the question, the word “combat” is most closely associated with the word “fight.” This is because combat is a physical confrontation between two or more people, usually involving the exchange of blows. A quarrel, conflict, or feud, on the other hand, is not necessarily physical.