The correct answer is - Philippines.
The Battle of Leyte was a battle that took place in Leyte Gulf on the island nation of the Philippines. The battle was between the United States and Australia on one side, and Japan on the other side. The battle took place in order for the Japanese to be pushed out of the Philippines, which were very important and strategic islands.
The Battle of Layte is considered as the biggest naval battle in World War II, and maybe even the biggest naval battle of all time, though opinions about it are split.