Which process made an increase in chemical energy for cell activities in organisms living on the earth possible

Metabolism is the process that is responsible for an increase in chemical energy for cell activities in organisms living on the earth possible.

Explanation:

Metabolism is the set of the chemical reactions that occurs in the living cells. All the living organisms needs some energy for growth and reproduction. Metabolism is the process that continues the chemical process in the organisms and activates the organisms to convert the chemical energy that stored in the molecules into other form of energy which can be used for the cellular process.  

b. the carbon cycle ensures living things have a source of hydrogen

the correct answer is c   with the systems