When Yao Jumps into the Cold Swimming Pool, His Testicles

When Yao jumps into the cold swimming pool, his testicles seem to move up and closer to his body. Why?

A) His vas deferens and dartos muscles are contracting in response to the cold.
B) His cremaster and dartos muscles are contracting to keep his testes warm.
C) His spermatic cord is relaxing in order to keep his sperm warm.
D) His dartos muscle is contracting in order to cool his sperm.