The correct option is C GnRH
Hypothalamus secretes Gonadotropin Releasing Hormones (GnRH) which stimulates the secretion of gonadotropins - Luteinizing Hormones (LH) and Follicle Stimulating Hormones (FSH).
LH acts on the Leydig cells and stimulates the production of androgens which in turn stimulate spermatogenesis.
FSH stimulates Sertoli cells to produce factors required for spermiogenesis