Answer
There are 2 possible values of $m_s$ for this orbital: $[+\frac{1}{2},-\frac{1}{2}]$.
Work Step by Step
The spin quantum number $m_s$ refers to the orientation of the spin axis of an electron. An electron can only spin in 2 directions and these directions are opposite from each other.
$m_s$ can only have 2 possible values no matter which orbital being mentioned, which are $+\frac{1}{2}$ and $-\frac{1}{2}$.
