Answer:
a) Open the DNS settings on your router and try using a different DNS.
Explanation:
The DNS or domain name service is a protocol that majorly assigns a URL string to an IP address. This is because the IP address as a number is easily forgotten.
In the question above, the operator could not access the websites with the URL name but can confirm connectivity to the site with its IP address. This means that the IP address can be used to access the websites directly, so, the DNS protocol is either not configured or is down.