Consider a Feistel cipher with four rounds. Remember that in a Feistel cipher the plaintext block P is split into left and right halves, P={LO, Ro), and for each round i=1,2,...n new left and right halves are computed according to the rules L; = Ri-7, and R; = L-1 F(Ri-1,K;). The ciphertext after the fourth round is C = (L4, R4). What is the cipher text in terms of LO, RO, and/or the subkey(s), for the round function F(Ri-4, Ki) = 0? 1.(L, R) 2.(Ro, Lo) O 3. (Lo, Ro K4) 4. (Lo, Roe K3)