Please answer and explain the answer in detail.

337 A cybersecurity analyst is currently auditing a new Active Directory server for compliance. The analyst uses Nessus to do the initial scan, and Nessus reports the following: PluginID 10955 11210 12350 12345 | IP 192.168.1.215 192.168.1.215 192.168.1.215 192.168.1.215 Port microsoft-ds (445/tcp) microsoft-ds (445/tcp) netbus (135/udp) ftp (21/tcp) Which of the following critical vulnerabilities has the analyst discovered? A. Known backdoor B. Zero-day C. Path disclosure D. User enumeration