A Chief Security Office`s (CSO`s) key priorities are to improve preparation, response, and recovery practices to minimize system downtime and enhance organizational resilience to ransomware attacks. Which of the following would BEST meet the CSO`s objectives? 

Answer options:

A. Use email-filtering software and centralized account management, patch high-risk systems, and restrict administration privileges on fileshares.
B. Purchase cyber insurance from a reputable provider to reduce expenses during an incident.
C. Invest in end-user awareness training to change the long-term culture and behavior of staff and executives, reducing the organization`s susceptibility to phishing attacks.
D. Implement application whitelisting and centralized event-log management, and perform regular testing and validation of full backups.

D