The Rotational Kinetic Energy of a Diatomic Molecule Can Take $\omega$

The rotational kinetic energy of a diatomic molecule can take the form:

A) (1/2) m $\omega$ 2
B) (1/2) I $\omega$ 2
C) [m1m2/(m1 + m2) ]r2 $\omega$ 2
D) (1/2) mv2
E) 1/2 $\mu$ $\omega$ 2