Match the valves of human heart in column I with the respective opening they guard in column II and select the correct option.

	Column I		Column II
i	Eustachian valve	a.	Opening of pulmonary aorta
Ii	The besian valve	b.	Left atrioventricular aperture
Iii	Mitral valve	c.	opening of inferior vena cava
Iv	Semilunar valve	d.	opening of coronary sinus

Apply the relevant identity from the chapter and substitute the values established in the previous step, keeping the original constraint in view.

Use the simplified expression to isolate the unknown, then plug the result back into the question setup to confirm the working is internally consistent.

Cross-check against a boundary or limiting case. Both the dimensional balance and the qualitative behaviour at the extreme should agree with the candidate answer.

Combine the steps above to identify the correct option. The remaining choices each fail at least one of the consistency, dimensional, or boundary checks.