Consider the El Gamal encryption scheme, a symmetric encryption scheme (KG,E,D), and the following hybrid encryption scheme having an encryption algorithm that, on input a public key (G,q,g,h), where h=g^x, returns (c1,c2). For which of the following c1,c2 values (and assuming a suitable definition of the key generation and decryption algorithms) does the hybrid encryption scheme satisfy indistinguishability in the presence of chosen message attack?
A. c1=g^y, c2=E(k,m), where k = g and y is random
B. c1=g^y, c2=E(k,m), where k = h and y is random
C. c1=g^y, c2=E(k,m), where k =g^y and y is random
D. c1=g^y, c2=E(k,m), where k = h^y and y is random
Please explain your reasoning