The correct option is B Retardation in milk ejection
Two primary hormones that are needed for lactation are prolactin and oxytocin.
Prolactin is synthesised by the lactotrophs (lactotrophs are prolactin producing cells present in the anterior pituitary).
Prolactin functions primarily in milk biosynthesis or milk production and the development of mammary glands.
Oxytocin is produced by neurosecretory cells of the hypothalamus and stored in the posterior pituitary. Oxytocin stimulates the contraction of myoepithelial cells that surround the alveoli causing the milk to be ejected into the ducts leading to the nipple. If there is a deficiency of oxytocin on the mammary gland then there will be a discrepancy in the milk ejection.
Decrease in adipose tissue and apoptotic cell death of glandular tissues are the processes that happen in the mammary gland post lactation, during mammary gland involution (returning of the lactating gland to a morphologically near pre-pregnant state).