To facilitate encrypted bulk data transfer using the TLS protocol, the shared secret key that is sent from the client to the server is encrypted with which key?

The client public key cannot encrypt a secret intended for the server because the server does not hold the client's private key and therefore cannot decrypt it.

Using the client's private key would produce a digital signature readable by anyone with the client's public key, not a confidential message to the server.

The client encrypts the pre-master secret with the server's public key, ensuring only the server - possessing the corresponding private key - can decrypt it and complete the symmetric session key derivation, as specified in RFC 5246 for TLS handshake key exchange.

The server's private key is kept secret on the server and is used by the server for decryption, never by the client for encryption.