Comprehensive and Detailed Explanation: The greatest risk to laptop computers is data exposure in case of theft or loss. The most effective safeguard is full disk encryption, which ensures that even if the device is stolen, data remains unreadable without the encryption key. * Disabled USB ports (A): Prevents some forms of data exfiltration but does not protect stored data. * MFA (C): Protects user authentication but not the data if the disk is removed. * Passkey phrases (D): Improves authentication strength but is weaker than encryption for data protection. # ISACA Reference: CISA Review Manual 27th Edition, Domain 5 (Protection of Information Assets), section on endpoint security and encryption controls.