Comprehensive Detailed Explanation:The best approach to address the risk of a zero-day attack is mitigation. Here’s an explanation of each option:

A. Avoid

Explanation: Avoiding risk would mean discontinuing the use of the asset, which is not feasible for high-value assets that are essential to operations.

B. Transfer

Explanation: Transferring risk would involve outsourcing or obtaining insurance, but this does not directly reduce the threat of a zero-day exploit.

C. Accept

Explanation: Accepting the risk means acknowledging it without implementing countermeasures, which is not advisable for high-value assets at risk from sophisticated attacks.

D. Mitigate

Explanation: Mitigation involves implementing technical or administrative controls to reduce the impact of an attack. For zero-day exploits, this could include installing network-based protections, enhancing monitoring, or applying threat intelligence to detect or contain potential exploit attempts.