Which set of configurations resolves the issue?

Refer to the exhibit.

Traffic from the branch network should route through HQ_R1 unless the path is unavailable. An engineer tests this functionality by shutting down interface on the BRANCH router toward HQ_R1 router but 192.168.20.0/24 is no longer reachable from the branch router.

Which set of configurations resolves the issue?
A . HQ_R2(config)# ip sla responder
HQ_R2(config)# ip sla responder icmp-echo 172.16.35.5
B . BRANCH(config)# ip sla 1
BRANCH(config-ip-sla)# icmp-echo 172.16.35.1
C . HQ_R1(config)# ip sla responder
HQ_R1(config)# ip sla responder icmp-echo 172.16.35.2
D . BRANCH(config)# ip sla 1
BRANCH(config-ip-sla)#icmp-echo 172.16.35.2

Answer: D