Amazon Elastic Block Store (Amazon EBS) is the correct choice, as it provides persistent block storage that automatically replicates within a single Availability Zone, offering high availability and durability. This suits the company's requirement because, unlike instance store volumes, Amazon EBS volumes persist independently of the life of the instance and can thus provide more durable block storage. Moreover, Amazon EBS provides a variety of volume types to cater to different performance needs. S3 is not a block storage solution, and EFS is a file storage service, which does not meet the requirement of block-level storage. While instance store provides temporary block-level storage, the data is lost if the instance is stopped, terminated, or if the underlying hardware fails, which does not meet the requirement for persistent storage.