What is pre colonial philippines

The history of the Philippines between 900 and 1565 begins with the creation of the Laguna Copperplate Inscription in 900 and ends with Spanish colonisation in 1565. The inscription records its date of creation in the year 822 of the Hindu Saka calendar, corresponding to 900 AD in the Gregorian system.

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answer; i believe that the correct answer is (agriculture);

d. it adversely affected american productivity