Parturition is induced by a complex neuroendocrine mechanism involvin…

The correct answer is Option (2) → (A), (C) and (D) only

Parturition is the process of childbirth. Signals from the fully developed foetus and the placenta cause mild contractions of the uterus, called the foetal ejection reflex. This makes the mother’s pituitary release oxytocin, which causes stronger contractions until the baby is delivered. NCERT says this complex neuroendocrine mechanism involves cortisol, estrogens and oxytocin.

(A) Cortisol — Correct. It is one of the three hormones named in the mechanism.

(B) Prolactin — Incorrect. It is not named in the mechanism of parturition. It is the hormone linked with milk production in the mammary glands.

(C) Estrogens — Correct. They are one of the three hormones named in the mechanism.

(D) Oxytocin — Correct. It strengthens the contractions of the uterine muscle.

NCERT Extract:
Parturition and Lactation – “… Parturition is induced by a complex neuroendocrine mechanism. The signals for parturition originate from the fully developed foetus and the placenta which induce mild uterine contractions called foetal ejection reflex. This triggers release of oxytocin from the maternal pituitary. Oxytocin acts on the uterine muscle and causes stronger uterine contractions, which in turn stimulates further secretion of oxytocin.”