In Terms of an Atom's Electron Configuration, the Letters K

Multiple Choice

In terms of an atom's electron configuration, the letters K, L, M, and N refer to

A) different shells with n equal to 1, 2, 3, or 4 respectively.
B) different sub shells with ℓ equal to 1, 2, 3, or 4 respectively.
C) the four possible levels for the magnetic quantum number.
D) the four possible quantum numbers.
E) none of the above answers.