Which of the following secretes testosterone?

$A$: The male urethra is longer than the female urethra.
$R$: It carries both urine as well as semen.

Given below is a diagrammatic sketch of a portion of the human male reproductive system. Which of the following parts contributes to the maximum portion of semen?

Sertoli cells are also called

$A$: The scrotum acts as a temperature regulator for the testes.
$R$: The wall of the scrotum is supported by dartos muscles,which help in the positioning of the testes.

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.