Which of the following is an important nitrogenous excretory component of urine under marine conditions?

Correct option is B

Correct Answer: (b) Trimethylamine oxide (TMAO)
Explanation:
→ TMAO is a key osmoregulatory compound in marine fishes, stabilizing proteins against high urea levels.
→ Excreted as part of nitrogenous waste in marine environments.
Information Booster:
→ Helps counteract destabilizing effects of urea in elasmobranchs.
→ Increases with depth as pressure adaptation.
→ Important biochemical marker in marine species.
Additional Information: Ammonia dominates in freshwater teleosts, urea in elasmobranchs.