Match the items given in column I with those in column II and select the correct option given below:

Column I	Column II
a. Tricuspid valve	(i) Between left atrium and left ventricle
b. Bicuspid valve	(ii) Between right ventricle and pulmonary artery
c. Semilunar valve	(iii) Between right atrium and right ventricle

The correct option is C a (iii )., b ( i )., c ( ii )
Valves are the structures which prevent the backflow of blood in the circulatory system.

• TRICUSPID VALVE:

The opening of the right atrium into the right ventricle is guarded by a tricuspid valve. This valve has three flaps (leaflets) that open and close, allowing blood to flow from the right atrium to the right ventricle. It prevents the backflow of deoxygenated blood from the right ventricle to the right atrium.

• BICUSPID VALVE:

The opening of the left atrium into the left ventricle is guarded by a bicuspid valve or mitral valve. It has two flaps. It permits blood to flow one way only, from the left atrium into the left ventricle. It prevents the backflow of oxygenated blood from the left ventricle to the left atrium.

• SEMILUNAR VALVES:

Semilunar valves allow the flow of blood from the ventricles into the main arteries (aorta and pulmonary artery). There are two semilunar valves in the heart.

• The opening of the right ventricle into the pulmonary artery is guarded by the pulmonary semilunar valve.
• The opening of the left ventricle into the aorta is guarded by an aortic semilunar valve.