The Native Peoples of Virginia (Powhatans)succumbed to the Europeans Because

The native peoples of Virginia (Powhatans) succumbed to the Europeans because they  

A) died in large numbers from European diseases.
B) lacked the unity necessary to resist the well-organized whites.
C) were no longer a resource for food once the Virginians began growing their own crops.
D) were not a reliable labor source and could be disposed of without harming the colonial economy.
E) All of these