Which of the following protocols are part of IPsec? Choose three.

The correct choice includes ESP, ACH, and IKE, which are all integral components of the IPsec framework used for securing Internet Protocol communications through encryption and authentication.

ESP, or Encapsulating Security Payload, provides confidentiality, integrity, and authentication for the data being transmitted. It is essential for ensuring that the data remains private, meaning unauthorized entities cannot access it during transmission.

IKE, or Internet Key Exchange, is a protocol used to set up a secure communications channel by negotiating the encryption keys and methods. IKE facilitates the establishment of a secure association between the two communicating parties, ensuring that the encryption and authentication processes can occur in a reliable manner.

ACH refers to the Authentication Header (AH) but seems to have been slightly misidentified in the answer choice provided; the focus remains primarily on the valid components of IPsec relevant to the question context. Thus, this reinforces the understanding of how IPsec protocols work together to create a secure transmission layer over the Internet.

Other options include incorrect or irrelevant protocols that do not belong to the IPsec suite, confirming that the selected answer encompasses the key protocols necessary for the secure exchange of data.