Refer to the exhibit.

We have to configure the link which will need 2 IP addresses, 1 for each port on each Router. We also need 2 spare IPs for future growth, so overall we need 4 usable IP addresses. If we consider using the /30 (255.255.255.252) mask, it will give us 2^2 (=4) i.e., total 4 IPs and 2 usable IPs, which doesn’t fulfil the given requirements. So, we can consider using the next /29 (255.255.255.248) mask, which gives us 2^3 (=8) i.e., total 8 IP address and 6 usable IP addresses, which perfectly fulfil the given requirements.