Answer:
A. menopause
Explanation:
Menopause is a condition most common among most middle-aged women, whereby the reproductive hormones natural declines. The ovaries of women of this age stops producing eggs every month, as menstruation stops.
When a woman doesn't see her period for straight 12 months, it can be concluded that menopause have set in with aging. Symptoms such as sleep distortion, weight gain, muscle aches etc also can be noticed. Anxiety and depression also sets in as can be noticed in their mood.
Therefore, the most likely cause for the symptoms experienced by Alexis is menopause.