The narrative point of view in this excerpt allows the reader to experience
O Rainsford's feelings as he enters the room.
Rainsford's feelings about his host.
Rainsford's impression of the dining room.
O Rainsford's impression of the island.

O Rainsford's impression of the dining room.

Explanation:

Richard Connell's short story "The Most Dangerous Game" revolves around the famed hunter Sanger Rainsford and his change of fortune when he was left stranded in an island famed for hunting humans as a game by the island's barbaric owner General Zaroff.

In the given excerpt, the narrator reveals the "dining room to which Ivan conducted (Rainsford)". The impression that the hall was "of feudal times with its oaken panels, its high ceiling, its vast refectory table where twoscore men could sit down to eat" reveals the outline of the enormous dining hall where Rainsford was conducted to eat with Zaroff. This narrative point of view allows the reader to experience the impression of the dining room.

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."