Laura Is 45 Years Old, and Her Husband Shane Is

Multiple Choice

Laura is 45 years old, and her husband Shane is 48 years old. They already have a child and want to have another child. Their physician states that their chances of conceiving a child are extremely low. Which of the following is the most likely reason for this reduced ability to bear children?

A) Shane has a very high sperm count.
B) Laura and Shane are genetically incompatible.
C) Laura and Shane are not from the same ethnicity.
D) Laura is too old to bear children.