Manx Cats Have No Tails

Multiple Choice

Manx cats have no tails.When two Manx cats are bred together there is always a one third chance that a kitten will have a tail.When a Manx cat is bred to a cat with a normal tail there is a one-half chance that a kitten will have a tail.Which of the following is the best explanation for this?

A) The Manx genotype exhibits variable expression.
B) The Manx phenotype is dominant,but the allele is a recessive lethal.
C) The Manx phenotype is dominant epistatic.
D) The Manx phenotype is caused by gene interactions.
E) The Manx phenotype is a result of heteroplasmy.