Suppose That Round Is the Dominant Allele for a Pea;

Suppose that round is the dominant allele for a pea; the recessive allele produces a wrinkled pea. How can true-breeding pea plants having round peas be obtained with the least amount of work?

A) perform a testcross of the plants with wrinkled peas to determine which are true breeding
B) perform a testcross on the plants with round peas to determine which are true breeding
C) perform multiple crosses between plants with round peas until one emerges that seems true breeding
D) perform multiple crosses between plants with wrinkled peas until one emerges that seems true breeding