The tiny bodies within cells that supply essential energy for function, growth, and repair are known as:

Mitochondria tiny bodies within cells that supply essential energy for function, growth, and repair. Mitochondria Theory States that aging is due to the decay of mitochondria. Emphasis on a decay of mitochondria-tiny bodies within cells that supply essential energy for function, growth, and repair. 

i would go with b

cytokinesis occurs after telophase so that eliminates d

and the entire reason for cytokinesis is for cellular reproduction

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.