You Have an Asynchronous Processing Application Using an Auto Scaling

You have an asynchronous processing application using an Auto Scaling Group and an SQS Queue. The Auto Scaling Group scales according to the depth of the job queue. The completion velocity of the jobs has gone down, the Auto Scaling Group size has maxed out, but the inbound job velocity did not increase. What is a possible issue?

A) Some of the new jobs coming in are malformed and unprocessable.
B) The routing tables changed and none of the workers can process events anymore.
C) Someone changed the IAM Role Policy on the instances in the worker group and broke permissions to access the queue.
D) The scaling metric is not functioning correctly.