For a molecule to absorb IR, why must the molecule\'s vibrations cause fluctuations in the dipole moment of the molecule?

• A. Because for absorption to occur, the radiation must interact with the electric field caused by changing dipole moment
• B. Because a change in dipole moment lowers the energy required for electronic transitions
• C. All of the above
• D. Because fluctuations in the dipole moment allow the molecule to deform by bending and stretching