Which statement best describes how digital signatures work?

Question $4$ Answer

a$.$

The sender hashes the message or file to produce a message digest and applies the chosen encryption algorithm and their private key to it$.$ This is the signature. The recipient uses the sender$$s public key and applies the corresponding decryption algorithm to the signature, which will produce a matching message digest only if the message or file is authentically from the sender$.$

b$.$

The sender hashes the message or file to produce a message digest and applies the chosen decryption algorithm and their public key to it$.$ This is the signature. The recipient uses the sender$$s private key and applies the corresponding encryption algorithm to the signature, which will produce a matching message digest only if the message or file is authentically from the sender$.$

c$.$

The sender hashes the message or file to produce a message digest and applies the chosen decryption algorithm and their private key to it$.$ This is the signature. The recipient uses the sender$$s public key and applies the corresponding encryption algorithm to the signature, which will produce a matching message digest only if the message or file is authentically from the sender$.$

d$.$

The sender encrypts the message or file with their private key and hashes the encrypted file to produce the signed message digest. This is the signature. The recipient uses the sender$$s public key and applies the corresponding decryption algorithm to the signature, which will produce a matching message digest only if the message or file is authentically from the sender$.$