Subnet Address (15 points). Consider a router that interconnects three subnets: Subnet 1, Subnet 2, and Subnet 3. Suppose all of the interfaces in each of these three subnets are required to have the prefix 137.99.17/24. Also suppose that Subnet 1 is required to support up to 80 interfaces, and Subnet 2 and 3 are each required to support up to 40 interfaces. Provide three network addresses (of the form a. b.c. d/x) that satisfy these constraints. Please justify that your design works, i. e., the address blocks of the three subnets do not have any overlap, the address block of each of three subnets is within 137.99.17/24, and each of the subnets has a sufficient number of IP addresses.