Environmental variation:
a. affects genotypic expression of characters.
b. has no effect on phenotype.
c. tends to blur together the phenotypes associated with different genotypes.
d. does not direct selection.

A) affects genotypic expression of characters.

Explanation:

Environmental variations  cause several affects on the  genotypic expression of characters. Genotype is defined as the genetic that prepare in the individual so that it has production of protein which after that involving with the environmental components result in the physical characteristic named as phenotype. Therefore, environmental variation cause more affect on the genotypic expression more than itself.

you can have just about every answer you can think of