Digital certificates used transport Layer security (TLS) support which of the following?

While server identity verification is a function of TLS certificates, this answer pairs it with 'data confidentially' which is a misspelling and incomplete description compared to the more comprehensive answer D which includes non-repudiation controls.

Input validation is an application-layer security control used to prevent injection attacks and is not a function of digital certificates or TLS.

Multi-factor authentication is an identity verification method requiring multiple credential types and is not a direct function provided by TLS digital certificates.

Digital certificates in TLS provide non-repudiation through digital signatures that cryptographically bind a party to their communications, ensuring they cannot deny having participated. They also enable data encryption by facilitating the exchange of symmetric keys through public key cryptography, ensuring confidentiality of data in transit. Together, these represent the core security functions that TLS certificates are designed to support.