In a mutation, which of the following types of cells is MOST LIKELY to be passed from a parent to its offspring?

A mutation in a skin cell due to ultraviolet (UV) light and not wearing sunscreen.
A mutation in a kidney cell due to a virus having the opportunity to enter the cell.
A mutation in a hair cell due to chemicals in hair care products.
A mutation in a sperm cell due to being a gamete required for reproduction.