Q45

Consider routing table of an organization’s router shown below:

$$\begin{array} {|l|l|l|} \hline \text{Subnet Number} & \text{Subnet Mask} & \text{Next Hop} \\\hline 12.20.164.0 & 255.255.252.0 & \text{R1} \\\hline 12.20.170.0 & 255.255.254.0 & \text{R2} \\\hline 12.20.168.0 & 255.255.254.0 & \text{Interface 0} \\\hline 12.20.166.0 & 255.255.254.0 & \text{Interface 1} \\\hline \text{default} & & \text{R3} \\\hline \end{array}$$

Which of the following prefixes in $\text{CIDR}$ notation can be collectively used to correctly aggregate all of the subnets in the routing table?