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 expected phenotypic ratio in the F₁ generation is

A) 9:3:3:1.
B) 100 percent of one phenotype.
C) 1:1.
D) 1:2:1.
E) none of these.