You Are Troubleshooting a Network Issue a User Is Having

Multiple Choice

You are troubleshooting a network issue a user is having.After having changed his network adapter to static addressing,he can no longer reach the internet.However,the machine resolves Internet names to IP addresses.Observe the adapter's configuration below,and determine the problem.
IP Address: 172.31.20.103
Subnet: 255.255.255.0
DNS Server: 172.31.20.251
Gateway address: 172.31.19.254

A) Gateway is outside of the user's subnet
B) Change subnet mask to 255.255.255.128
C) The gateway no longer has a route to your ISP,so it does not deliver packets
D) DNS is providing incorrect or old resolution information,and the IP addresses given are no longer accurate