A directly connected route is automatically generated when a router interface has a valid IP address and the interface is operational.

In this topology, R2 connects directly to two networks: 10.0.0.0/24 through GE0/0/1 and 20.1.1.0/24 through S1/0/0.

Therefore, R2 already has the necessary routing information to forward packets between these two directly connected networks. Additional static routes are not required on R2.

However, R1 initially knows only its directly connected network, so it requires a static route toward 20.1.1.0/24 using R2 as its next hop.

Similarly, R3 requires a static route toward 10.0.0.0/24 through R2.

These routes provide bidirectional connectivity between interfaces on R1 and R3.

Therefore, the router that does not require additional static routes is R2.