Assertion: Magnetic moment of helium atom is zero.
Reason: All the electron are electron are paired in helium atom orbitals.

Options

A. Both A and R are true and R is also the correct explanation of A .
B. Both A and R are true but R is not the correct explanation of A.
C. A is true but R is false.
D. A is false and R is also false.

Answer

A