Answer:
C. Uninterrupted power supply.
Step-by-step explanation:
Uninterrupted power supply or UPS is device that is connected to the main power supply of a system or a network of computer systems to provide power, when the main power supply is down. It promotes power redundancy for a reliable network.
Network cloaking device is used to hide a networks domain name, while it is being broadcast across.
The backup punch card is an outdated technology used for recording digital data.
Service level agreement is a documented agreement between the services providers and companies, on the method or form of service to be rendered.