39. Leptin.
| a. | is the toxin causing tissue necrosis in leprosy. | |
| b. | is a neuro-transmitter produced by the hypothalamus leading to immature and reckless behaviour. | |
| c. | is a growth factor produced by the pubertal testicle with its main effect on Sertoli cells. | |
| d. | is a hormone produced by fat. |