Exam NSE8 topic 1 question 35 discussion

The FortiGate is used as an IPsec gateway at a branch office. Two tunnels, tunA and tunB, are established between this FortiGate and the headquarters IPsec gateway. The branch offices subnet is 10.1.1.0/24. The headquarters subnet is 10.2.2.0/24. The desired usage for tunA and tunB has been defined as follows:
- sessions initiated from 10.1.1.0/24 to 10.2.2.0/24 must be routed out over tunA when tunA is up
- sessions initiated from 10.1.1.0/24 to 10.2.2.0/24 have to be routed out over tunB when tunA is down
- sessions initiated from 10.2.2.0/24 can ingress either on tunA or on tunB
Which static routing configuration meets the requirements?
A)

B)

C)

D)