The scrotum is a thin skin pouch that contains the......

The Leydig's cells secrete

What is the average number of sperm in a single ejaculation?

Explain the difference between the following terms:
$(1)$ Testosterone - Progesterone
$(2)$ Vasa efferentia - Vas deferens

Given below are two statements:
Statement-$I$: The scrotum helps in maintaining the low temperature of the testes.
Statement-$II$: Low temperature,compared to the normal internal body temperature,is necessary for spermatogenesis.
In the light of the above statements,choose the most appropriate answer from the options given below.

Identify $A$ to $F$ in the diagram given below.