Answer:
Option C.
Step-by-step explanation:
The arrangement of electrons in their orbital follows certain rules.
The Hund's rule practically explained how electrons are distributed in their orbitals.
The Hund's rule states that electrons distributed among the orbitals of the same shell singly (without partner) before pairing occurs.
In the filling of these electrons in their orbitals, we fill in the electron without pairing first because electrons tends to repel each other before filling with the opposite spin as shown in the attached photo.