First step is to make the presumptive diagnosis of osteoporosis from the clinical vignette . ( The supposed subtype in our patient is postmenopausal osteoporosis)
After this the next step is to make an association with the lab findings The primary defect is a deficiency of estrogen . Normally estrogen decreases osteoclast activity by
Net effect of losing estrogen is increased osteoclast activity ,and in this question by extension RANK L concentration .
NOTE : ALP which is an indicator of osteoblast activity does not change/ increase in osteoporosis , as such avoid all options with an increase in osteoblast activity