option (c) is correct
let n=3 (A,B,C) and number of selector lines =3(i.e A,B,C) then number of input lines will be 8 .by putting $I_{0},I_{1},I_{2},I_{3},I_{4},I_{5},I_{6},I_{7}$=1 or 0 we can easily implement by 3 selector line.
Now ,let number of selector line =2(i.e A,B) and input be C then we can also implement it. correct me if i am wrong.