An organization is evaluating their email authentication mechanisms to bolster security. They wish to ensure that emails are not only transmitted securely but also retain proof of sender identity and message integrity upon delivery. They are looking to implement a method that provides a cryptographic signature for emails, which can be validated using a public key in the DNS. The method should confirm that the message was not tampered with in transit. To accomplish this, which DNS record type should they configure to contain the public key for this cryptographic verification?
TXT
MX
AAAA
CNAME