$2.$ A large organization with a large block address $(12\mathrm{.}44\mathrm{.}184\mathrm{.}0/21)$ is split into one medium$-$size company using the block address $(12\mathrm{.}44\mathrm{.}184\mathrm{.}0/22)$ and two small organizations. Assume that the first small company uses the block $(12\mathrm{.}44\mathrm{.}188\mathrm{.}0/23).$ a$.$ What is the remaining block that can be used by the second small company? b$.$ Explain how the datagrams destined for the two small companies can be correctly routed to these companies if their address blocks are still part of the original company. I. A packet with the destination address of $12\mathrm{.}44\mathrm{.}185\mathrm{.}110$ II$.$ A packet with the destination address of $12\mathrm{.}44\mathrm{.}190\mathrm{.}25$ III. A packet with the destination address of $12\mathrm{.}44\mathrm{.}189\mathrm{.}24$