A recently discovered zero-day exploit utilizes an unknown vulnerability in the SMB network protocol to rapidly infect computers. Once infected, computers are encrypted and held for ransom. Which of the following would BEST prevent this attack from reoccurring? 

Answer options:

A. Configure the perimeter firewall to deny inbound external connections to SMB ports.
B. Ensure endpoint detection and response systems are alerting on suspicious SMB connections.
C. Deny unauthenticated users access to shared network folders.
D. Verify computers are set to install monthly operating system, updates automatically.

A