the answer is A ,when x=0,g(x)is-1,so when u add x into the g(x),which is given below,u can find C,D,E,g(x) is no equal to -1,when you add x=1 into g(x)(A,B),you can find g(x) of B is 0,which is no equal the answer giving above(g(x)=2),but A is all right.