When the denominator = 0 and the numerator does not, you get a vertical asymptote. That said a = - 1
If the exponents on the highest variable are the same in the horizontal asymptote is the division of coefficient on the top with the bottom. In plain English what that means is that if you make m = 1 then the coefficients are 2 and 1 (2 in the numerator and 1 in the denominator). If m is any other value greater than 1 there is not a horizontal asymptote.
C <<<====answer.
Third one down.