Answer: c. Allied naval forces halted the advance of the Japanese in the Pacific.
Step-by-step explanation:
The Japanese had been defeating every territory they wanted in the Pacific and were victorious at it in the beginning of WW2. Their army had a lot of morale therefore and this needed to be broken.
The battles of the Coral Sea and Midway were the battles to do so. The U.S. inflicted a devastating defeat on the Japanese in the Battle of Midway by sinking four of their aircraft carriers. These were never replaced through the war and significantly weakened the ability of the Japanese to attack with the navy.