plaintext Y3JlZGl0LWNhcmQtbnVtYmVyCg==

plaintext Y3JlZGl0LWNhcmQtbnVtYmVyCg==
A . The resulting plaintext data is base64-encoded. To reveal the original plaintext, use the base64 –decode command.
B . The data is corrupted. Execute the encryption command again using a different data key
C . the user doesn’t have permission to decrypt the data, therefore Vault returns false data so as not to reveal if the data was actually encrypted by Vault
D . Vault is sealed, therefore the data cannot be decrypted. Unseal Vault to properly decrypt the data

Answer: A

Explanation:

All plaintext data must be base64-encoded. The reason for this requirement is that Vault does not require that the plaintext is "text". It could be a binary file such as a PDF or image. The easiest safe transport mechanism for this data as part of a JSON payload is to base64-encode it.

Reference link: – https://learn.hashicorp.com/vault/encryption-as-a-service/eaas-transit