What does the follicular phase signify in the menstrual cycle?

The follicular phase signifies the beginning of the menstrual cycle, starting on the first day of menstruation. This phase is characterized by the development of follicles in the ovaries under the influence of hormones like follicle-stimulating hormone (FSH), which leads to the maturation of an egg. As the follicular phase progresses, the follicles produce estrogen, which helps to rebuild the uterine lining in preparation for a potential pregnancy.

The other options do not accurately represent the characteristics of the follicular phase. It clearly does not occur after ovulation, nor is it the last phase before menstruation—those roles are attributed to the luteal phase. Additionally, it does not end with fertilization; rather, it ends with ovulation, when the mature follicle releases the egg. Thus, the correct choice effectively captures the essential nature of the follicular phase as the commencement of the menstrual cycle.