Which statement contrasts moles and warts?

• A. Warts are caused by bacteria, while moles are pigmented spots
• B. Warts can spread and are a virus, while moles are just a spot of extra melanin
• C. Moles are contagious, while warts are not
• D. Warts are always flat

Answer: (B)

Warts and moles differ in what causes them and whether they can spread. Warts are infections caused by human papillomavirus and can spread to other areas of the skin or to others through contact. Moles are clusters of pigment-producing cells (melanocytes) in the skin and are not contagious. The statement that warts are viral and can spread, while moles are simply pigmented spots, best captures this contrast. Warts aren’t caused by bacteria, and moles aren’t contagious; they aren’t necessarily just spots of extra melanin and can vary in appearance from flat to raised. The other options misstate these facts, such as implying bacteria cause warts, or that moles spread, or that warts are always flat.