A Fibre Channel switch has eight ports and all ports must be operational from 8 AM to 8 PM, Monday through Friday. However, a failure of Port 2 occurs on a particular week as follows:Monday = 10 AM to 12 PM Wednesday = 4 PM to 9 PM Thursday = 4 PM to 7 PM Friday = 3 PM to 6 PM Saturday = 9 AM to 1 PMWhat is the availability of Port 2 in that week?
选项：

A: 70%
B: 71.6%
C: 78.3%
D: 80%