Final answer:
Elderly male horses may develop tumors in specific areas. The part of the male urogenital tract shared by the urinary and reproductive systems is the urethra. The urinary bladder is only related to the male urinary system, not the reproductive system.
Step-by-step explanation:
The question pertains to the anatomy of elderly male horses and their propensity to develop tumors on certain parts of their body. According to veterinary studies, elderly male horses have a higher risk of developing tumorous growths in specific areas.
Regarding the male urogenital tract, which is shared by both the urinary and reproductive systems in mammals, the answer to your question is d. the urethra. The urethra serves as a passage for the elimination of urine from the urinary bladder and also allows for the discharge of semen during reproductive ejaculation in males.
When considering structures related only to the male urinary system, as opposed to the male reproductive system, the correct answer would be a. urinary bladder. The urinary bladder's primary function is to store urine before urination, which pertains exclusively to the urinary system without any direct function in the reproductive process.