A thin layer of water is transparent but a very thick layer of water is

Between the spectator and the item, there is a very thin film made of water. Although there is a lateral shift in the vision in the thick layer, it is not considered opaque since nothing is seen in opaque.
Step 1:

The emerging ray changes laterally when a light ray is incident obliquely on a parallel-sided glass slab. The term "lateral shift" refers to the angle that exists between the incident and emerging rays.

A side gilded spine position is referred as as a lateral shift. When the vertebra above moves laterally to the right or left in proportion to the vertebra below, the trunk follows. This is known as lateral shift.

The upper trunk and shoulders move to the right or left as a consequence.
Step 2:
The lateral displacement is exactly proportional to the thickness of the glass slab. Lateral shift depends on thickness. The light rays are bent as they penetrate a piece of glass. The ultimate separation between the incident and emerging rays is now known as the lateral displacement.

Hence, the correct answer is option A.