Final answer:
A) Cryptorchidism is the condition where one or both testes do not fully descend into the scrotum, which can cause fertility issues due to inadequate temperature for sperm production.
Step-by-step explanation:
The condition where one or both testes do not fully descend into the scrotum is known as A) Cryptorchidism. This typically should occur during the seventh month of the development period of a male fetus, as the testes move through the abdominal musculature into the scrotal cavity. If this process doesn't happen, the condition of cryptorchidism is diagnosed, which can lead to reduced fertility as the temperature in the abdominal cavity is too high for sperm production, which needs to be slightly lower than the regular body temperature.
The testes are surrounded by protective connective tissue layers, with the outermost being the tunica vaginalis and the tougher inner layer called the tunica albuginea. Within the protective layers, seminiferous tubules housed in lobules are where sperm develops. The testes are part of the male reproductive system, which also includes the epididymis and vas deferens, both vital for the transport and maturation of sperm.