A manager in a small office is asking if it is possible to limit network access to a particular website during business hours. Apparently, all users are spending an excessive amount of time on the site preventing them from completing their work-related tasks. Which of the following is the best solution to accomplish the request from the manager while not limiting access to other websites?

a) Implement MAC filtering on the SOHO router for the PCs that are accessing the site.
b) Configure a firewall and add the site the users are visiting to the whitelist.
c) Configure a firewall with content filtering on the PCs of users who are visiting the site.
d) Implement a blacklist on the firewall and add the site the users are visiting.