Answer:
The correct answer choice to the question: What mistake did General Douglas MacArthur make in December 1941, would be: He miscalculated the strength of the Japanese and was forced to retreat.
Step-by-step explanation:
The United States knew that the Japanese intended to invade the Philippines and moved to try and prevent such a thing from happening. General MacArthur was stationed on the Philippines, trying to stop Japan, and did not forsee the intent of the Japanese to outmaneuver the U.S and attack its most powerful and important defense system in Pearl Harbor. As such, when the attack took place on December 8, 1941, MacArthur and the men under his command, as he was the General entrusted with the Pacific Fleet forces, were taken completely unawares. This happened in part because MacArthur miscalculated the true strength of the Japanese, and not only did this miscalculation cost him Pearl Harbor, but also, the loss of the defense of the Philippines.