What should the administrator do to protect these communications in this failover situation?

Refer to the exhibits.

Exhibit 1

Exhibit 2

All of the switches in Exhibit 1 are routing switches. Exhibit 2 shows the routes configured on these switches. The direct (connected) routes are not shown, but assume that links are configured with the IP addresses shown in Exhibit 1.

The network administrator wants to protect communications between clients and servers in case Link 1 fails.

What should the administrator do to protect these communications in this failover situation?
A . Add a redundant route to 10.1.10.0/24 on Switch-4 and a redundant route to 10.1.20.0/24 on Switch-1.
B . Add a redundant route to 10.1.20.0/24 on Switch-1 and a redundant route to 10.1.20.0/24 on Switch-2.
C . Add a redundant route to 10.1.10.0/24 on Switch-1 and a redundant route to 10.1.20.0/24 on Switch-4.
D . Add a redundant route to 10.1.20.0/24 on Switch-1 and a redundant route to 10.1.10.0/24 on Switch-2.

Answer: A