A convex lens is held 45 cm above the bottom of an empty tank. The image of a point object at bottom of tank is formed 36 cm above the lens. Now a liquid is poured into the tank upto a height of 40 cm above the bottom. It is found that distance of image of same point object at the bottom of the tank is 60 cm above the lens. Refractive index of liquid is

A

1.33

B

1.37

C

1.40

D

1.60