Final answer:
The name of the quantum number mI is the Magnetic Quantum Number. The magnetic quantum number describes the orientation of the region in space occupied by an electron with respect to an applied magnetic field. Therefore, the correct option is 3) Magnetic Quantum Number.
Step-by-step explanation:
The name of the quantum number mI is the Magnetic Quantum Number. The magnetic quantum number, mI, describes the orientation of the region in space occupied by an electron with respect to an applied magnetic field. The allowed values of mI depend on the value of the principal quantum number (n) and can range from -n to n in integer steps.