Which of the following is the MOST effective method of preventing deliberate internal security breaches? 

Answer options:

A. Screening prospective employees
B. Well-designed firewall system
C. Well-designed intrusion detection system (IDS)
D. Biometric security access control

B

Reference: https://www.techrepublic.com/article/strategies-for-preventing-internal-security-breaches-in-a-growing-business/