Answer:
C. rr
Step-by-step explanation:
The dominant genotype will always be denoted by the capital version, or in this case R.
The round pea shape is dominant to the wrinkled pea shape, which means that, in the Punnett Square, the combinations of RR, Rr, rR, will all come out to be round pea shape.
The last box, rr, would be the one that gives the wrinkled phenotype.
In this case, by ratio, wrinkled phenotype show up 25%
by ratio, round phenotype show up 75%.