Gross Primary Productivity Refers to the Total ____

Multiple Choice

Gross primary productivity refers to the total ____.  

A) quantity of solar energy available to the ecosystem in a given period of time
B) quantity of solar energy reaching a given area of the ecosystem
C) energy captured initially by the producers
D) energy used by the heterotrophs of the ecosystem in a given period of time
E) energy used by the producers for their growth and reproduction