Read the following paragraph and answer the question. Give ONLY the answer, no other words or explanation.

For example:

Answer: <most likely answer, as short as possible>.

Paragraph: 
The male reproductive system consists of structures that produce sperm and secrete testosterone. They include the penis, testes, and epididymes.


Question: The penis, testes and epididymes are structures in what male anatomical system?
reproductive
Reproductive system.