What is a lockout device?

A、Adevicethatpreventsaccidentalstartingofequipmentthatyouareworkingon
B、Adevicethatenablesthestaringofequipmentthatyouareworkingon
C、Adevicethatensuresthattheequipmentcannotbeoperateduntilthelockoutdeviceisremoved.“
D、Bothaandc