Question

The largest group of non-willing people brought to America were taken from

Spain
Africa
India

Answer 1

For sure Africans. Spaniards usually came at their own will, sometimes forced but most of the time their own will. Indians I believe where the same, they fled to America usually for a better life.
Africans were forced to come to USA as slaves/indentured servants.

Answer 2

The largest group of non-willing people brought to America were taken from Africa