I'm not entirely sure what you mean, but a fit animal is one that is able to out-compete with other animals in its ecosystem. It possesses some kind of advantage, which makes it easier to compete with others for food, water, shelter, and mates. Due to these qualities, the animal is obviously able to live for a good deal of time and have a greater chance of producing viable offspring.
Basically all of the choices given are failure of negative feedback mechanisms to maintain homeostasis. The correct option among all the options that are given in the question is the last option or option "E". I hope that this is the answer you were looking for and it has come to your help.
Fish would be renewable since they can be reproduced.
We cant make gold, or oil, and gasoline comes from oil, so all are non-renewable
Mitosis goes in the blank
... whereby the body procedures glucose from amino acids and glycerone molecules