An organization has several accounts managed within AWS Organizations. The DevOps Engineer in charge of the network AWS account has established an AWS Transit Gateway to direct all of the company's outgoing traffic, which is then directed through a firewall appliance for inspection. The firewall appliance logs all types of event severities such as CRITICAL , ERROR , HIGH , MID , LOW , and ERROR which are all sent to Amazon CloudWatch Logs. During a recent security audit, no alerts were discovered for events that could cause disruptions to business continuity. The company has required that the security team receive an alert for immediate remediation when any CRITICAL events occur. Which of the following is the MOST suitable solution that the DevOps Engineer should implement?