Direction.
In these questions, two words will be given to you, and these two words will have some kind of a relationship which relates them in a particular way. After finding this relationship, you have to pick the right option which has words related in a similar way:
OPAQUE : LIGHT : :
Absorbent : liquid
Desert : sand
Autoclave : germ-free
Hermetic : air
Correct Answer :
D. Hermetic : air
Something that is opaque blocks light completely. Likewise, something that is hermetic is completely sealed against the escape or entry of air.