What may be the problem?

You are the Network Admin, and you get a compliant that some of the websites are no longer accessible. You try to ping the servers and find them to be reachable. Then you type the IP address and then you try on the browser, and find it to be accessible. But they are not accessible when you try using the URL.

What may be the problem?
A . Traffic is Blocked on UDP Port 53
B . Traffic is Blocked on UDP Port 80
C . Traffic is Blocked on UDP Port 54
D . Traffic is Blocked on UDP Port 80

Answer: A