The first menstruation which begins at puberty is called:

The correct answer is Option (2) → Menarche

Option (1) Menopause — Incorrect. Menopause is the permanent stop of menstrual cycles, at around 50 years of age, not their beginning.

Option (2) Menarche — Correct. The first menstruation, which begins at puberty, is called menarche. Menstruation stops around 50 years of age; that is menopause.

Option (3) Menstrual cycle — Incorrect. It is the whole repeating cycle of events from one menstruation to the next, not the first menstruation.

Option (4) Ovulation — Incorrect. Ovulation is the release of an ovum from the Graafian follicle, in the middle of each cycle.

NCERT Extract:
Menstrual Cycle – …