Estrogen Increases Bone Mass and Bone Mineral Density By

Estrogen increases bone mass and bone mineral density by:
1) reducing bone resorption by directly preventing osteoclast differentiation, activity, and survival and indirectly by stimulating the secretion of calcitonin.
2) increasing collagen synthesis and osteoid formation.
3) enhancing the absorption of calcium across the intestines.

A) 1, 2, 3
B) 1, 2
C) 2, 3
D) 1, 3