Answer:
B. It became clear that the nations that lasted the longest would win.
Step-by-step explanation:
This is true for the Western front. On the East, it was a lot more back and forth and Germany had a plan to kick Russia out of the war and with the new troops on the Western front it would be a lot easier to break the stalemate. Since offensive technology and strategy did not develop near fast enough as the defensive technology and tactics that meant that on the Western front you could not push without suffering a great loss of life. So they sat and waited to see which army would give in first, and the French army did mutiny a lot at that time. In the end, Germany had no supplies and had to surrender the war in 1918.