Which of the following is used to validate the integrity of data?

CBC (Cipher Block Chaining) is a mode of operation for block ciphers primarily used to ensure confidentiality through encryption, not to directly validate data integrity.

Blowfish is a symmetric-key block cipher used for encrypting data to achieve confidentiality, not for verifying the integrity of data.

MD5 (Message-Digest Algorithm 5) is a cryptographic hash function that produces a unique fixed-size hash value, or message digest, from an input of arbitrary length. This hash value acts as a digital fingerprint; if the original data is altered, even slightly, the regenerated MD5 hash will differ, thereby allowing for the detection of any integrity compromise.

RSA is an asymmetric encryption algorithm primarily utilized for confidentiality, digital signatures, and key exchange, rather than directly validating data integrity through a hash.