What is the function of Prolactin?

Prolactin primarily functions to promote breast development and plays a critical role in lactation. This hormone is produced by the anterior pituitary gland and is significant during pregnancy and after childbirth, as it helps prepare the mammary glands for milk production. In addition to its role in breastfeeding, prolactin also has various effects on reproductive and metabolic functions, but its main association is with the development of breast tissue and the initiation of milk secretion.

The other options relate to different hormones and functions; for example, skin pigmentation is typically influenced by melanocyte-stimulating hormone (MSH), the stimulation of the adrenal cortex is related to adrenocorticotropic hormone (ACTH), and metabolism regulation is primarily governed by hormones like insulin and thyroid hormones. Thus, the primary role of prolactin in breast development makes the first option the correct choice.