The author's hypothesis concerning the cold prehistory of life would be most weakened if which of the following were true? A. Cosmic rays are unlikely to trigger the formation of simple molecules. B. Tunneling occurs only in a narrow band of temperatures around zero degrees Kelvin. C. The synthesis of interstellar formaldehyde can be activated by means other than cosmic rays. D. Simple molecules can be synthesized by means of tunneling. E. Classical chemical reactions do not occur at temperatures close to absolute zero.