The part of the feed check valve which moves up and down automatically under the pressure of water on its gun metal seat is called _____

The part of the feed check valve which moves up and down automatically

1.	The part of the feed check valve which moves up and down automatically under the pressure of water on its gun metal seat is called _____
A.	Check valve
B.	Fusible plug
C.	Flange
D.	Safety valve
Answer» B. Fusible plug