What allowed West Africans to resist the initial and subsequent Portug

What allowed West Africans to resist the initial and subsequent Portuguese attempts to conquer their nations in the 1400s?

A) The strategic use of powerful small canoes frustrated Portuguese military efforts even before they landed on unknown shores.
B) The massive and well-equipped West African armies overwhelmed the fewer, poorly equipped Portuguese soldiers on land.
C) The Portuguese were not resistant to deadly African diseases.
D) The Portuguese were half-hearted and ambivalent about their attempts to conquer these African nations.

ANSWER
Answer: A