The correct option is a) Lower.
If two orbitals have the same (n + 1) value, the orbital with the lower value of n has lower energy, and therefore it is filled first.
The energy of an electron in an atom is primarily determined by its principal quantum number (n). Orbitals with the same (n + 1) value are part of different principal energy levels. When comparing two orbitals with the same (n + 1) value, the one with the lower principal quantum number (n) is closer to the nucleus and thus experiences a stronger electrostatic attraction. This results in a lower energy level for the orbital.
According to the Aufbau principle in electronic configuration, electrons fill orbitals starting with the lowest energy level. As the principal quantum number (n) increases, the energy level of the orbital also increases. Hence, among orbitals with the same (n + 1) value, the one with the lower n value is filled first.
Therefore, the correct option is a) Lower.