You are performing a vulnerability assessment and are currently attempting service discovery. If you send a packet with the SYN flag set and receive an RST packet in return, what does this tell you?

A $$ The device is reachable, but the port is closed, and the service is not available.

The device is reachable, the port is open, and the service is available.

C

The target device is behind a firewall.

$$ The device is behind a firewall, and the port is open.