In Its Lowest Quantum State, a Diatomic Quantum Mechanical Rotator $\frac { \hbar ^ { 2 } } { 2 I }$

In its lowest quantum state, a diatomic quantum mechanical rotator has a rotational energy of

A) $\frac { \hbar ^ { 2 } } { 2 I }$
B) $\frac { \hbar ^ { 2 } } { I } .$
C) zero.
D) none of the given answers.