A valve which allows the water to flow in one direction but prevents its flow in the reverse direction, is known as

A valve which allows the water to flow in one direction but prevents i

1.	A valve which allows the water to flow in one direction but prevents its flow in the reverse direction, is known as
A.	sluice valve
B.	reflux valve
C.	air relief valve
D.	pressure relief valve
Answer» C.