Which of the following is the primary female sex organ?

The correct answer is Option (3) → Ovaries

A primary sex organ is the organ that makes the gametes and the sex hormones. In the male it is the testis. In the female it is the ovary, which makes the ovum and the ovarian hormones.

Option (1) Mammary glands — Incorrect. They are accessory organs that produce milk after childbirth. They make no gametes.

Option (2) Uterus — Incorrect. The uterus is an accessory duct where the embryo implants and grows.

Option (3) Ovaries — Correct. They produce the ovum and the steroid hormones, so they are the primary female sex organs.

Option (4) Cervix — Incorrect. The cervix is the lower narrow part of the uterus that opens into the vagina. It is part of the birth canal.

NCERT Extract:
The Female Reproductive System – …