Why are the testes in human beings and mammals situated outside the abdominal cavity within a pouch called the scrotum?

• A
  There is not enough space in the pelvic area for the testicles to be housed internally.
• B
  The scrotum helps in maintaining the low temperature of the testes, $2.5^{\circ}C$ lower than the normal body temperature, which is required for spermatogenesis.
• C
  The scrotum helps in maintaining the high temperature of the testes, $2.5^{\circ}C$ higher than the normal body temperature, which is required for spermatogenesis.
• D
  Providing more space for the growth of the epididymis.