What is a charge that improves a species' change of survival?

a. variation

b. adaptions

c. genetics

d. phenotype

First of all, it is a change, not a charge.
Phenotype is physical manifestation of gene(physical), not a change, so it is not phenotype.

Variation is a state of being genetically diverse, but it is not a change, therefore it is not variation.

Genetics is the name of a field, and it is not a change.

Adaption are changes of a population overtime, through natural selection.

It is adaptions

Ribonuclease activity is a type of nuclease that catalyzes the degradation of rna into small components.