Final answer:
The testes are the primary reproductive organs of the male reproductive system and the urethra is a passage duct, not accessory organs. The true accessory organs include the seminal vesicles, prostate gland, and bulbourethral glands.
Step-by-step explanation:
The student has asked which of the listed options are not classified as accessory organs of the male reproductive system. The accessory organs in the male reproductive system typically include the seminal vesicles, the prostate gland, and the bulbourethral (Cowper's) glands. These organs play a role in the production, nourishment, and transport of semen.
The testes are not an accessory organ but rather the primary reproductive organs, where spermatogenesis, or the production of sperm, occurs in the seminiferous tubules. The epididymis is where sperm mature and are stored, and while important, it is not considered an accessory gland. The urethra is a duct that allows for the passage of sperm and urine out of the body, but it is also not classified as an accessory gland. So, the correct answer to the question is that the testis (a) and the urethra (c) are not accessory organs of the male reproductive system.