Mendel breed two different types of true breeding plants together. one parent had white flowers, and the other had purple flowers. all of the offsprings of the parents had purple flowers. the allele for purple flowers would be represented by:

C. a capital letter. an allele is represented by one letter so that gets rid of b and d. since there doesn’t need to be two purple alleles for the flower to be purple (we know this because the white flowers have white alleles which combine with the purple) that means it’s the dominant allele, making it an uppercase letter.