Final answer:
The correct answer that describes a violation of the Pauli exclusion principle is option c. This means that arrows in the same subshell should have different directions.
Step-by-step explanation:
The correct answer that describes a violation of the Pauli exclusion principle is option c. This means that arrows in the same subshell should have different directions. According to the Pauli exclusion principle, no two electrons in the same atom can have exactly the same set of all four quantum numbers. This means that two electrons can occupy the same orbital only if their spin quantum numbers have different values, which is represented by arrows with opposite directions in an orbital diagram.