Which is a correct set of values of m for one of the subshells of n = 2?
–1, 0, 1
–1, –2, 0, 1, 2
–1, –2, –3, 0, 1, 2, 3
–1, –2, –3, –4, 0, 1, 2, 3, 4

The answer is -1, 0, 1.

For a given value of principal quantum number (n), the corresponding angular quantum number (l) value is equivalent to (n - 1). From this, you can get the set of values for mangetic quantum number m is:

m = -l, ..., 0, ..., l

So for n=2, l = 1, and m = -1, 0, 1