Answer:
Follicle stimulating hormone (FSH)
Explanation:
The correct answer for the given question that fills up the blank is " follicle stimulating hormone (FSH) ".
The follicle stimulating hormone (FSH) is responsible for the initiation of the follicle egg development.
The follicle stimulating hormone (FSH) also stimulates the secretion of the estrogen during the first half of the ovarian cycle.
