The sloughing off of older cells from the surface of the skin is called

A. an inability to lay down new bone
Bone formation is the role of osteoblasts, not osteoclasts.

B. an inability to lay down cartilage
Cartilage is formed by chondroblasts, unrelated to osteoclasts.

C. an inability to regulate calcium
Osteoclasts resorb bone, releasing calcium into the bloodstream. Defective osteoclasts impair this process, disrupting calcium homeostasis.

D. an inability to create matrix
Osteoclasts break down bone matrix, they don’t create it. Matrix creation is done by osteoblasts.

A. she must wear hats a lot
Wearing hats has no scientific link to causing or expressing genetic baldness.

B. she must produce enough testosterone
Male pattern baldness is an androgen-dependent trait, meaning that even if a woman inherits the gene, it requires the presence of testosterone (or dihydrotestosterone, DHT) to be expressed. Elevated androgen levels in women (e.g., in PCOS) may trigger expression.

C. she must dye her hair
Hair dye affects only the external hair shaft and has no genetic or hormonal influence on baldness.

D. she must produce enough estrogen and progesterone
Estrogen and progesterone actually have protective effects on hair. Decreased levels of these hormones (e.g., after menopause) may unmask androgenic effects, but they do not directly cause male pattern baldness expression.