Answer:
C. nslookup
E. ping
Explanation:
The two commands that would confirm this assumption would be nslookup and ping. The command nslookup will show you a mapping of the DNS and the IP address, this includes the name server and how it is being translated to the correct IP address. The ping command will send a small piece of data to the IP address of the website that you are trying to access and listen back for a response. If a response is received it means that the website was reached correctly and is fully operational. Both of these commands combined will allow you to determine whether the technician's assumption was correct.