Ans: C
Note that the graph opens upwards, then $m>0$. Note also that the $y$-intercept of the graph is negative, then $n<0$. Hence, $m>0$ and $n<0$.
Note that the graph opens upwards, then $m>0$. Note also that the $y$-intercept of the graph is negative, then $n<0$. Hence, $m>0$ and $n<0$.
