Which of the following secretes Testosterone in a normal male?

Within the testis between the seminiferous tubules there are nests of lipid granules containing cells called Leydig cells. They are concerned with the secretion of testosterone into the blood stream. Besides secreting testosterone, Leydig cells also secretes estradiol contributing 20 -30 % of of the total circulating estradiol, the remainder is derived from the peripheral aromatization of androgenic substrates. The human Leydig cells are characterized by the presence of crystalloid inclusions, the crystals of Reinke whose functional significance is not known. Ref: Ganong's Review of Medical Physiology, 24e, chapter 23