If L = 5, then the magnetic quantum number "mL" can be equal to a. -4, -3, -2, -1, 0, +1, +2, +3, +4
b. -5, -4, -3, -2, -1, 0, +1, +2, +3, +4, +5
c. 0, 1, 2, 3, 4
d. 0, 1, 2, 3, 4, 5

b. -5, -4, -3, -2, -1, 0, +1, +2, +3, +4, +5

Each orbital in an atom consists of 4 quantum numbers  

n is the principal quantum number.  

l is the angular momentum / azimuthal quantum number  

ml, the magnetic quantum number  

ms, the electron-spin quantum number  

Value of n: positive integer  

value of l: s = 0, p = 1, d = 2, f = 3 , ..(n-1)

ml value: between -l to + l  

ms value: +1/2 or -1/2  

So for L=5, mL value : -5 to +5