Given the protocol: Alice to Bob - "I'm Alice", R Bob to Alice - {R,Ks}Alice Alice to Bob - {R+1,Ks}Bob Where Ris the nonce, Ks is the session Key, {...} is encryption with specified PUBLIC key. Which of these sentences is correct? O The protocol ensures mutual authentication, but is subject to replay and MiM attacks O The protocol ensures mutual authentication, avoid replay attack and MiM attack O The protocol doesn't ensure mutual authentication