Bone remodeling

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.

A. he could develop brittle bones
Brittle bones are more associated with osteoporosis or osteogenesis imperfecta, not primarily from vitamin D deficiency due to lack of sunlight.

B. he could develop very dense bones
Dense bones are seen in conditions like osteopetrosis, which results from defective osteoclast activity-not lack of sunlight.

C. he could develop soft, bowed bones
Lack of sunlight leads to vitamin D deficiency, impairing calcium absorption, which causes rickets in children and osteomalacia in adults, both of which involve soft, weakened bones that may bow under body weight.

D. he could develop nightmares
While isolation might impact mental health, this has no direct link to skeletal effects or bone physiology.