Manx cats have no tails. When two Manx cats are bred together there is always a one third chance ...

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.