Joe, a user, reports intermittent connectivity issues, but a technician notices that the only time Joe has issues is when he is logged into the database. Losing connection after authenticating to a database, but still having access to network resources such as file/print services and email, would MOST likely be caused by: 

Answer options:

A. an incorrect DHCP gateway setting
B. a duplicate IP address
C. NTP synchronization
D. ACL configuration

D