Refer to the exhibit.

Invalid Credentials:

The debug output shows an "AuthFailure" error, indicating that AWS was not able to validate the provided access credentials. This usually points to incorrect or invalid AWS access or secret keys configured in the AWS Lab SDN connector (Option C).

Clock Skew:

Another common reason for authentication failures in AWS API calls is a clock skew between the FortiGate device and AWS. AWS requires that the system time of the client making the API call is synchronized with its own time, within a small margin. If there is a significant time difference, AWS will reject the credentials (Option B).

Other Options Analysis:

Option A is incorrect because the AWS API supports XML version 1.0.

Option D is incorrect as the error message does not indicate an issue with connecting on port 401.

Option E is incorrect because the error is related to authentication, not the absence of instances.

References:

AWS API Authentication: AWS API Security

FortiGate AWS Integration Guide: FortiGate AWS Integration