单选题Node ’A’ and ’B’ have two network adapters connected to different networks. Adapter 1 is assigned the address 192.168.0.10 with a subnet mask of 255.255.255.0. Adapter 2 is assigned the address 24.76.1.200 with a subnet mask of 255.255.240.0.  What is 

Node ’A’ and ’B’ have two network adapters connected to different networks. Adapter 1 is assigned the address 192.168.0.10 with a subnet mask of 255.255.255.0. Adapter 2 is assigned the address 24.76.1.200 with a subnet mask of 255.255.240.0.  What is the minimum number of additional adapters per node required to eliminate a network adapter as a single point of failure？（）