Which of the following encryption types would be used to protect company information when stored on a cloud server being shared by multiple companies?

SSL (Secure Socket Layer) is a deprecated transport-layer protocol that encrypts data in transit between client and server over a network - it provides no protection for data already stored at rest.

TLS (Transport Layer Security) also secures data during network transmission only and does not protect data that is sitting idle on a storage device.

Whole disk encryption protects a disk against unauthorized physical access, but on a shared cloud server all tenants share the same encrypted disk, so once the disk is mounted and decrypted by the provider, one tenant's data is not isolated from another's.

File and folder level encryption encrypts individual files or directories with keys controlled by their respective owners, so even when multiple companies share the same physical or virtual cloud storage, each company's data remains cryptographically isolated and unreadable to other tenants. This granular approach is the appropriate choice for multi-tenant environments because it provides data-level separation that whole-disk or transport encryption cannot offer on shared hardware.