Historically, Why does the Philippines have a claim over Sabah?

• A. The sultan of Sulu, who received the territory as a gift, has given the Philippines Government Power to reclaim his territory.
• B. The Malays, the third wave of migrants to the country, own the territory.
• C. Sabah was formerly a part of the Philippines archipelago.
• D. The Philippines government bought it from the Sultan of Brunei