Security awareness and training is the most effective primary countermeasure against social engineering because these attacks exploit human trust, curiosity, urgency, and lack of familiarity with deception tactics rather than purely technical weaknesses. In CEH guidance, phishing, vishing, and baiting succeed when users fail to recognize red flags such as unexpected requests, pressure to act quickly, suspicious links or attachments, caller spoofing, or offers that seem too good to be true. A structured awareness program directly reduces the chance of disclosure by teaching employees how to identify common pretexts, verify unusual requests, and follow safe reporting procedures.

While identity verification (option B) is an important practice, employees typically perform it correctly only when they have been trained on verification steps, escalation paths, and what “good verification” looks like under pressure. Two-factor authentication (option C) helps protect accounts even if credentials are stolen, but it does not prevent employees from sharing sensitive information such as customer data, internal documents, OTP codes, or approving fraudulent requests—many social engineering campaigns aim beyond passwords. Policies and procedures (option D) are necessary, but policies alone are often ignored or misunderstood without ongoing training, reinforcement, and real-world simulations.

CEH-aligned best practice is a layered approach: start with awareness training, reinforce it with clear handling policies, require verification for sensitive requests, conduct phishing simulations, and ensure employees know how to report suspicious emails/calls immediately. This combination reduces both successful compromise and the impact of attempts, but training is the foundational priority because it directly targets the human element being attacked.