Question

smokers not only develop wrinkles and yellow teeth, they also lose\underline{qquad}, which increases their risk of osteoporosis,\bigcirc bone density\bigcirc hair follicles\bigcirc skin glow

Explanation:

Osteoporosis is a condition characterized by reduced bone strength, primarily linked to low bone density. The question connects the lost factor to osteoporosis risk, so bone density is the logical choice. Hair follicles and skin glow are unrelated to osteoporosis.

Answer:

bone density