Answer:
C. He summarizes a "colossal military disaster."
Step-by-step explanation:
"Their Finest Hour" is one of the most famous and significant speeches by Winston Churchill. In this speech, Churchill begins by summarizing "a colossal military disaster." He talks about how the French High Command failed to withdraw the Northern Armies from Belgium at the moment when they knew that the French front was decisively broken at Sedan and on the Meuse.