Two rays of light are incident normally on water. Both
the rays pass through glass slabs of different heights,
as shown in the given figure. Refractive indices of water
and glass are 4/3 and 3/2 respectively. If c is the speed
of light in vacuum, then the time difference between the
rays of light to reach the bottom is
AH/2c
B8H/9c
CH - h1 - h2/3c
Dh1 - h2/6c