The keys fell . . . . . . . . the pool of water.

Solution (By Examveda Team)

In the sentence "The keys fell . . . . . . . . the pool of water," the correct preposition is "into". The preposition "into" is used to indicate movement from outside to a point inside or within something. In this context, it implies that the keys fell and entered the pool of water, emphasizing the action of moving from one place to another, specifically into the water.

Option A: in – "In" indicates a position within a space or area but does not convey the sense of movement or motion into the pool. It would be used if the keys were already inside the pool.

Option C: on – "On" indicates a position above or touching the surface of something, but it does not imply movement. It would be incorrect here as it would mean the keys fell onto the surface of the pool, not into it.

Option D: to – "To" indicates direction or movement toward a destination but does not imply entering or going inside. It would suggest that the keys fell towards the pool but not necessarily into the water.

Therefore, the correct preposition is "into", as it properly indicates the motion of the keys falling and entering the pool of water.