What Is the Value of the Spin Quantum Number for an Electron

What is the value of the spin quantum number for an electron in a 3d orbital?

A) 3
B) 2
C) either $+ \frac { 1 } { 2 }$ or $- \frac { 1 } { 2 }$
D) $- \frac { 1 } { 2 }$
E) $+ \frac { 1 } { 2 }$