You add the DHCP Server Role on a server named TESTKING_SR04. You configure DHCP to support two subnets named Subnet A and Subnet B. Subnet A has a network ID of 172.16.0.0/16 and Subnet B has a network ID of 172.16.1.0/24. All client computers are reconfigured to receive IP addresses from DHCP. However, clients on Subnet B cannot access clients on Subnet A. What is the most likely cause of this problem?