Which of the Following Statement(s)is (Are)not True About Cylinder Valves

Which of the following statement(s) is (are) not true about cylinder valves?
1) Diaphragm valves cannot withstand pressure greater than 1500 psig.
2) Direct-acting valves are used for pressure greater than 1500 psig.
3) Diaphragm valves should not be used with anesthetic gases.
4) Stem leakage can occur with direct-acting valves.

A) 3
B) 2 and 4
C) 1 and 4
D) 1,2,and 3