The first thing you need to understand is that the American Navy won a battle. It did not win the war by succeeding at Midway. The Japanese did not surrender (Making B incorrect), nor was the Japanese Navy taken out of the war (making D incorrect). The coral sea battle took place in May and it was the first tactical victory by the Allies in the Pacific making A wrong.
Conclusion: A B D are all incorrect.
So what did happen? The Japanese had been defeated in the greatest sea battle of WWII. They were not completely taken out, but after that the initiative had been passed from the Japanese to the Americans.
What had been a defensive war for America now became an offensive one.
Answer: C