Final answer:
The release of an ovum from a follicle during the menstrual cycle is known as ovulation, which is the correct answer to the student's question.
Step-by-step explanation:
The process of releasing an ovum from a follicle is known as ovulation. Ovulation is a key part of the menstrual cycle and typically occurs around day 14 in a 28-day cycle. It marks the transition from the follicular phase to the luteal phase of the ovarian cycle. Rising levels of estrogen lead to a surge in luteinizing hormone (LH), which triggers the release of an oocyte from the ovary. The empty follicle then transforms into the corpus luteum, which secretes progesterone to maintain the endometrium in preparation for a potential pregnancy. Hence, the correct answer to the question is 'c. ovulation'.