Answer:
D m =

Explanation:
factor the expressions in the denominator and the numerator to simplify the expression:
=>

=>

to make a fraction undefined, the numerator should be 0, thus, we substitute the values of m from the options into the denominator to make the denominator equals to 0:
=>
=
=

in this case, the values of m from option D make the denominator of the fraction equals 0.