Answer
There are $~~5~~~$ possible values of $~~m_l$
Work Step by Step
For any value of $n$, the values of $l$ can be $~~~l = 0, 1, 2,...,(n-1)$
When $n=3$, then the values of $l$ can be $~~~l = 0, 1, 2$
For any given value of $l$, the values of $m_l$ can be $~~m_l = 0, \pm 1, \pm 2,...,\pm l$
If $l=2$, then the values of $m_l$ can be $~~m_l = -2, -1, 0, 1, 2$
There are $~~5~~~$ possible values of $~~m_l$
