Agree with Rajeed that the course needs to be updated. STS and EFS was on the exam. I had reviewed Amazon EFS documentation previously so I was comfortable with question. The question on EFS wasn't in depth but it made reference to basically a shared storage that can be accessed from multiple instances. I read the post on STS and did a quick review that helped. The EBS question was not covered in the course and would require a more indepth look at EBS an encryption.