Answer the following question given this paragraph: 

During adolescence, testosterone causes most of the changes associated with puberty. It causes the reproductive organs to mature. It also causes other adult male traits to develop. For example, it causes the voice to deepen and facial hair to start growing.


Q: During adolescence, what causes most of the changes associated with puberty?

 Choices:

- estrogen

- nicotine

- methane

- testosterone

A:
testosterone
