Which of the following tools is used for vulnerability scanning and calls Hydra to launch a dictionary attack?

Whisker is a web application vulnerability scanner focused on CGI-based vulnerabilities and does not integrate with Hydra to perform dictionary attacks.

SARA (Security Auditor's Research Assistant) is a network vulnerability analysis tool but does not specifically invoke Hydra to conduct dictionary-based credential attacks.

Nmap is a network discovery and port scanning tool, not a vulnerability scanner with built-in capability to call Hydra for login attacks.

Nessus is a widely-used vulnerability scanner that includes plugin support to call Hydra, a network login cracker, to launch dictionary attacks against services such as FTP, SSH, and HTTP. This integration lets Nessus test for weak credentials as part of a comprehensive vulnerability assessment, which is a documented capability distinguishing it from other scanners in this list.