Which of the following sentences requires a citation?
A. Any exposed semi susceptible to sunburn
B. Prolonged sun exposure can result in a burn
C. Some sunscreens have an SPF of 35 or higher.
D. One in five Americans will develop skin cancer by the age of 70.
Presents a factual claim about a significant health risk and should be supported by a credible source.
Therefore, the Correct Answer is D.