The right answer is B. Testicles
Control of testicular activity is performed by the hypothalamic-pituitary complex (or gonadotropic axis): the hypothalamus is an area at the base of the brain that contains clusters of neurons secreting hormones. It is attached to the pituitary gland via the pituitary stem. These neurons rhythmically emit flashes of action potentials. This activity triggers the pulsatile secretion of gonadotropin-releasing-hormone, or GnRH, a hypothalamic neurohormone.