What sea battle made it possible for the allies to eventually retake the philippines? battle of midway battle of leyte gulf battle of iwo jima battle of saipan

The best answer is Battle of the Philippine Sea otherwise known as the "Great Marianas Turkey Shoot". This battle ended any chance the Japs had of using sea or air power to protect Philippines from invasion and provided the US the jumping off place and support logistic's to invade Philippines. 

The battle of the coral sea was the sea battle that stopped Japan's expansion and the first Carrier group battle. 
The battle of Midway could be an answer. This battle was the turning point in the war with Japan and let eventually to the liberation of Philippines.

The answer is d. spain.