Which device is implemented within the hypervisor to monitor and filter traffic on the virtual network?

The correct answer is the virtual firewall, which is a crucial component in virtualized environments that rely on hypervisors. A virtual firewall monitors and controls the incoming and outgoing network traffic based on predetermined security rules and policies. By being integrated within the hypervisor, it effectively manages security for virtual machines (VMs) on the same host, ensuring that traffic between the VMs or between VMs and the outside world is monitored and secured.

In contrast, while a virtual VLAN can segment network traffic for better organization and security, it does not inherently provide filtering or monitoring capabilities like a firewall does. Smart card readers and digitizers are hardware interfaces used for different purposes, such as user authentication and input devices for graphic design, respectively, and are not related to network traffic monitoring. Therefore, the implementation of a virtual firewall is essential for maintaining security in a virtualized network environment.