Answer: C- Power
Explanation: A Tier 4 data center is fault-tolerant. it allows for the occurrence of any unplanned activity while still maintaining operations. Tier 4 data center specifications need IT equipment to have dual power inputs to permit maintenance of power distribution components.
A Tier 4 data center certification typically serve enterprise corporations and provide the following:
1. 99.995% uptime per year.
2. 2N+1 fully redundant infrastructure.
3. 96-hour power outage protection. Which means it must have a constant power supply.