What Precaution Should Be Observed When Wiring an Emergency Stop

Multiple Choice

What precaution should be observed when wiring an emergency stop pushbutton to a PLC?

A) It should be wired normally closed and programmed normally open.
B) It should be wired normally open and programmed normally closed.
C) Emergency stop pushbuttons should be hard-wired and, therefore, should not be wired to an input module.
D) It should be wired normally closed and programmed normally closed.