Which of These Statements Correctly Describes Why Methane and Carbon

Multiple Choice

Which of these statements correctly describes why methane and carbon dioxide are considered to be significant greenhouse gases?
I. Both have permanent dipole moments that change with vibration of the molecule.
II. Neither has a permanent dipole moment, but a dipole moment is produced when the molecule vibrates.
III. The concentration of carbon dioxide in the atmosphere increases when fossil fuels are mined and burned.

A) I only
B) II only
C) III only
D) I and III only
E) II and III only