Some Dogs Have Erect Ears; Others Have Drooping Ears

Multiple Choice

Some dogs have erect ears; others have drooping ears. Some dogs bark when following a scent; others are silent. Erect ears and barking are due to dominant alleles located on different chromosomes. A dog homozygous for both dominant traits is mated to a droopy-eared, silent follower. The phenotypic ratio expected in the F ₁ is

A) 9:3:3:1.
B) 100 percent of one phenotype.
C) 1:1.
D) 1:2:1.
E) 3:1.