Oxytocin is primarily involved in which of the following processes?

Oxytocin is a hormone that plays a crucial role in several reproductive processes, one of which is stimulating milk letdown during breastfeeding. When a baby suckles at the breast, sensory signals are sent to the mother’s brain, prompting it to release oxytocin. This hormone causes the milk-producing glands in the breast to contract, pushing the milk into the ducts and allowing it to flow to the nipple for the infant to drink. This process is often referred to as the "letdown reflex."

In addition to its role in lactation, oxytocin is also associated with various other functions, such as promoting social bonding and influencing maternal behavior. However, its specific and well-documented action in stimulating milk letdown makes it the most relevant answer to the question.

While the other choices touch on important physiological processes, they do not directly relate to the primary function of oxytocin. Regulating energy metabolism is typically overseen by hormones like insulin and glucagon, promoting follicle growth is mainly influenced by hormones like follicle-stimulating hormone (FSH) and luteinizing hormone (LH), and maintaining pregnancy involves several hormones, including progesterone and human chorionic gonadotropin (hCG). Thus, while these processes