Salesforce Marketing Cloud offers various encryption options when creating a new key in Key Management. The three encryption options that can be used are:

Asymmetric (B) - Asymmetric encryption uses a pair of keys (public and private) for encryption and decryption. This method is highly secure as the private key remains confidential.

RSA (C) - RSA is a specific type of asymmetric encryption. RSA stands for Rivest-Shamir-Adleman, and it is widely used for secure data transmission.

Symmetric (E) - Symmetric encryption uses the same key for both encryption and decryption. It is efficient for encrypting large amounts of data.