Which one of the following can't be used as an origin server with Amazon CloudFront?

Which one of the following can’t be used as an origin server with Amazon CloudFront?

Which one of the following can’t be used as an origin server with Amazon CloudFront?
A . A web server running in your infrastructure
B . Amazon S3
C . Amazon Glacier
D . A web server running on Amazon EC2 instances

Answer: C

Explanation:

Amazon CloudFront is designed to work with Amazon S3 as your origin server, customers can also use Amazon CloudFront with origin servers running on Amazon EC2 instances or with any other custom origin.

Reference: http://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/distribution-web.html