Searching for technology stack details on job listings can reveal valuable information about the technologies a corporation uses without interacting with the target systems or networks, thus remaining truly passive. When companies post job advertisements, they often list the skills and technologies they use, inadvertently exposing potential attack vectors to penetration testers. This information may lead to uncovering known weaknesses or exploits associated with the specified technologies. The other options are more intrusive, not strictly considered passive, or less likely to provide technology-specific details that can be targeted in an attack.