Assertion : An orbital cannot have more than two electrons, moreover, if an orbital has two electrons they must have opposite spins.
Reason : No two electrons in an atom can have same set of all the four quantum numbers.

Options

A. If both the assertion and reason are true statement and reason is correct explanation of the assertion .
B. If both the assertion and reason are true statement but reason is not a correct explanation of the assertion .
C. If the assertion is true but the reason is a false statement.
D. If both assertion and reason are false statements.

Answer

A

Explanation

According in Pauli's exclusion principle no two electrons in an atom can have same set of all the four quantum numbers. From this is follows that an orbital cannot have more than two electrons. If an orbital has two electrons then they have opposite spins.