Which of the following statements correctly reflects the most important consequence of Paull's exclusion principle? Click the answer you think is right.
a. An atomic orbital can hold a maximum of two electrons as long as they have the same spin.
b. An energy level can hold a maximum of two electrons of opposite spin.
c. An atomic orbital can hold a maximum of two electrons as long as they have opposite spins.
d. Orbits fill from lower to higher energy levels.