What Was Peculiar About the African Adaptation of Metallurgy

What was peculiar about the African adaptation of metallurgy?

A) Most African cultures failed to adopt metallurgy and remained dependent on stone tools and technology.
B) African cultures developed bronze toolmaking independently, but received iron working from the western Mediterranean.
C) African cultures never passed beyond bronze metallurgy.
D) African cultures received iron metallurgy from western Asia, but never developed copper metallurgy.