Question 4 (2.0 marks) Encryption of large blocks using TEA (or any fixed size block cipher), as you have done for one of the tasks in your assignment, can be achieved through the means of modes. We consider an Output Feedback Mode (OFB mode) operation for a block cipher which implements the decryption as Pi = C Ss[E(K,0;-1)] for i > 0, where C1,C2,C3 ... are the ciphertext and P1, P2, P3 ... are the plaintexts (messages). Given the ciphertext 10110100, the key = [1,1,0], Co = [1,1,1], and the following cipher: Input Output 000 110 001 111 010 011 100 101 100 010 101 110 111 011000001 Which one of the following is the plaintext, if the mode of operation is a 2-bit OFB cipher? A. plaintext: 11 00 10 00 B. plaintext: 11 10 11 00 C. plaintext: 11 10 10 01 D. plaintext: 11 01 10 01 E. plaintext: 11 10 10 00