Due to increasing human populations, there has become a global concern that our supplies will become scarce due to overuse and contamination.
a. fishing
c. carbon dioxide
b. farming
d. freshwater

are there any options you can choose from? ?

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.