Final answer:
The quantum number m represents the atom's orbitals, which are spherical regions where electrons are likely to be found.
Step-by-step explanation:
The orbital shape of an atom's electrons is represented by the quantum number m. The correct answer is b) Spherical regions where electrons are likely to be found. The m quantum number, also known as the magnetic quantum number, describes the orientation of the orbital in space. It indicates the number of different orientations an orbital can have within a subshell and ranges from -l to +l.