Fact 1: Testosterone stimulates the reproductive organs to develop into male organs.

Fact 2: For men, however, the hormone in question is testosterone.

Given the two facts above, answer the question "What stimulates the reproductive organs to develop into male organs?" with the following options: 
- a hormone
 - bioaerosols
 - Energy.
 - Energy
 - Leptospirosis
 - a doorbell
 - seeds
 - Chlorophyll


 

 a hormone        