The answer is urethra.
It is known that the kidneys are responsible for filtration of metabolic wastes from the blood and form urine. Urine is transported through the ureters to the urinary bladder. From the urinary bladder, urine is transported to the outside of the body by the urethra.
Answer: Coenzymes
Explanation:
Coenzymes are the small organic molecules that are often derived from the vitamins. It can be tightly or loosely bond to the enzymes.
Tighly bond ones are the prothestic groups and loosely bond ones are coenzymes like the products and substrate which binds to the enzyme and get released from it.
This component is very important for any reaction to take place. It bonds to the enzymes and helps in product formation.
I believe your answer is B :)