A company is hosting backend web services across Amazon EC2 Linux instances in public subnets in a VPC. A SysOps administrator tries to connect to the instance by using SSH but is unable to connect.
What could be the cause of the failed connection?

A. The security group does not allow inbound traffic on port 22.
B. The network ACL does not allow outbound traffic on port 80.
C. The security group does not allow outbound traffic on port 3389.
D. The network ACL does not allow inbound traffic on port 443.