homozygous recessive

1. Huntington’s disease is characterized by a late onset of nerve degeneration that leads to death.  The allele that causes the disease is dominant.  Lucille is homozygous dominant for the disease and Joe is homozygous recessive.  What is the probability that their children will have Huntington’s disease?

    1/4 or 25%
    2/4 or 50%
    3/4 or 75%
    4/4 or 100%