A user needs to determine whether an Amazon EC2 instance's security groups were modified in the last month.
How can the user see if a change was made?

A. Use Amazon EC2 to see if the security group was changed.
B. Use AWS Identity and Access Management (IAM) to see which user or role changed the security group.
C. Use AWS CloudTrail to see if the security group was changed.
D. Use Amazon CloudWatch to see if the security group was changed.