Respuesta :
Stalemate happened along the Western Front because the tactics of the offensive warfare had not developed while the technology of defensive warfare had. The invention of the machine gun had made it so that headlong charges of masses of soldiers were suicidal.
Answer:
B. Neither side was able to make progress in the war.
Explanation:
The problem says that by 1916, WWI was in a stalemate at the western front. A "stalemate" is basically a situation where the neither of the two opposing parties can advance and make a move in their favor.
The wording of choice B is a good match and a paraphrase of that definition.
Hope this helps!