Which of the following is the best example of protection against social engineering?

Social engineering often involves tricking individuals into revealing sensitive information or performing actions; verifying a user's identity through a pre-established, trusted method like a callback prevents imposters from succeeding. This method ensures the person on the other end is who they claim to be, directly countering common social engineering tactics.

Scanning for malware protects against malicious software but does not directly address the human manipulation aspect of social engineering.

Keeping default passwords is a major security vulnerability that social engineers might exploit if they learn the default, but it is not a protection against social engineering itself.

Connecting with people over social media increases exposure to potential social engineering attempts, rather than protecting against them.