Which of the following is a risk practitioner's BEST recommendation upon learning that an employee inadvertently disclosed sensitive data to a vendor?

Enrolling the employee in additional security training is a preventive measure for the future but does not address the immediate data breach incident itself.

Inadvertent disclosure of sensitive data constitutes a security incident requiring a structured and timely response. Invoking the incident response plan is the best recommendation because it outlines predefined steps for containment, eradication, recovery, and post-incident analysis, ensuring a systematic approach to mitigate harm, comply with regulations, and prevent recurrence.

Conducting an internal audit is a reactive measure to assess controls and compliance, which typically follows or runs in parallel with incident response, not as the primary immediate action.

Instructing the vendor to delete the data is an important step in remediation, but it is one specific action that should be part of a broader incident response plan, not the entire immediate recommendation.