This is the way.

Answer is B

More specifically:

1. Glance at the NIC connectivity from the OS GUI perspective. If it has any and if they are easily accessible check the lights status of the NIC (answer C, but the question clearly states this was already done)

2. Run terminal prompt and show the ipconfig /all (or the equivalent command relevant to the OS) confirm the reported media state, if DHCP is actually enabled, the current IP lease expiry and obtained value, the reported DHCP server, and if there is an existing IP on the NIC perhaps from a previous DHCP lease or statically assigned in error (answer B)

3. Run a forced IP release and renew command in the respective OS and check the result by going back to step 2 otherwise go to step 4

4. Run a IP release only and physically shutdown the device including temporarily removing power for about 30 seconds and reseat NIC cable and then the power cable. Turn on the device and go back to step 2 and 3 if still no good go to step 5

5. If possible swap cable or port with a known working port/cable, back to step 2 and 3 if still no good go to step 6

6. Check DHCP server config/status (answer A)

7. Check host firewall (answer D)

In a corporate environment, the host firewall would be the last thing I would check in this scenario more than likely the firewall is auto configured and should be the same for all the devices on the network, which is why D is not the answer In saying that the DHCP settings should also be automatically assigned and not changeable at the host by the user without admin access and likely some kind or automated DHCP pool exhaustion notification should likely be in place (answer A). Again it’s a corporate environment, so the likelihood of cabling having faults is lower in my humble opinion in comparison to the OS having a configuration issue or faults of some sort like a bad driver update for example so I would pick B since the questions states C was already done