Point Mutations Can Occur in Any Given Cell Type, but They

Point mutations can occur in any given cell type, but they mostly affect only that one cell and cells produced by it. What cell type, if mutated, would allow the mutation to be passed on to family members for generations?

A) glial cells, such as those that produce a myelin sheath
B) skin cells
C) white blood cells
D) gametes, such as an egg or sperm