What is Amazon Glacier?

A.
It’s a security tool that allows to “freeze” an EC2 instance and perform computer forensics on it.

B.
A security tool that allows to “freeze” an EBS volume and perform computer forensics on it.

C.
A low-cost storage service that provides secure and durable storage for data archiving and backup.

D.
You mean Amazon “Iceberg”: it’s a low-cost storage service.