Are the economic foundation for the coastal countries of west and central africa. a. agricultural products c. gold and silver b. manufactured goods d. all of the above

I just took the quiz and the answer is NOT  b manufactured goods

radiative zone

explanation    

radiative zone is the layer of the sun which energy is transferred away from the core by radiation. although, the core is the only part of the sun that produces an appreciable amount of heat through fusion. in fact, 99% of the energy produced by the sun takes place within 24% of the sun's radius.