What is the most probable cause of this problem?

The dns server is down.-in this case you can ping the ip address but not the host name. therefore there is a problem with host name to ip address resolution. dns is responsible for host name to ip address resolution and is the most probable cause of the problem.incorrect answers:a: dhcp is responsible for automating the assignment of ip configurations to computer systems on a tcp/ip network. however, we can ping the server by ip address. therefore dhcp cannot be causing the problem.b: you can ping the print server by ip address, therefore the print server cannot be down.d: you can log on to the certkiller .com network. therefore the remote access server cannot be causing the problem.references:david groth and toby skandier, network+ study guide (4th edition), sybex, alamedaca, 2005, pp. 136-144, 184.