This question is really testing whether you understand how quantum numbers relate to electron configuration, not just where an element is located on the periodic table. A common mistake is to assume that since nitrogen is in period 2, all of its electrons have n = 2. However, quantum numbers describe the orbitals that electrons actually occupy, so you always need to consider the full electron configuration.

Nitrogen has 7 electrons with the configuration: 1s² 2s² 2p³. The number in front of each orbital (the principal quantum number, n) tells you which energy level or shell the electron is in. This means that 2 electrons are in the first shell (n = 1, 1s), while the remaining 5 electrons are in the second shell (n = 2, 2s and 2p). The principal quantum number also determines which types of orbitals are possible, since l can range from 0 to n − 1. For nitrogen, this means electrons only occupy s and p orbitals in the ground state, so the possible azimuthal quantum numbers (l) are limited to:

Once you know the possible values of l, you can determine the magnetic quantum number (mₗ), which describes the orientation of an orbital in space. For each value of l, mₗ can take on all integer values from −l to +l. This means:

Since nitrogen has electrons in both s and p orbitals, the full set of possible magnetic quantum numbers is −1, 0, +1, which corresponds to answer choice A.

Please refer to this table to summarize how each quantum number is related: