Increased muscle mass is usually due to high testosterone, which doesn't play a big role in PCOS. The current cloze should be answered with "virilization" or any cause of it. PCOS is inaccurate and probably wrong.
Amboss doesn't mention anything about increased muscle mass.
If you want the answer to be PCOS, I recommend changing "increased muscle mass" to "oligoamenorrhea" or "amenorrhea" so it meets the criteria for PCOS.
Here is part of UTD
"Virilization — Signs of virilization, including frontal balding, clitoromegaly, increased muscle mass, or deepening of the voice, are seen when the serum testosterone concentration is more severely elevated (eg, over 150 ng/dL), which occurs in ovarian hyperthecosis and androgen-secreting ovarian or adrenal tumors. Although serum testosterone levels may be somewhat elevated in women with PCOS, they are not in a range that can cause virilization. )"
See discussion
