What is the formula for encryption using the RSA algorithm? M: Plaintext message, C: Ciphertext message, e: Encryption key, d: Decryption key

Group of answer choices

C $=$ M$^$e $($mod n$)$

C $=$ M$^$d $($mod n$)$

M $=$ C$^$e $($mod n$)$

M $=$ C$^$d $($mod n$)$