Mary is a carrier for a mutated gene that causes sickle cell disease. Which of the following statements is true about Mary?

A. If Mary has a child with someone who has sickle cell disease, there is a 50% probability their child would have the disease.
B. If Mary has a child with someone who does not have a mutated sickle cell allele, there is a 25% probability that the child will be a carrier.
C. If Mary has a child with someone who is also a carrier, there is a 50% probability their child would have the disease.
D. Mary has sickle cell disease.