Which Molecular Formula Is Consistent with the Following Mass Spectral

Multiple Choice

Which molecular formula is consistent with the following mass spectral data? M⁺• at m/z = 78, relative height = 23.5%
(M+1) ⁺• at m/z = 79, relative height = 0.78%
(M+2) ⁺• at m/z = 80, relative height = 7.5%

A) C₆H₆
B) C₃H₇Cl
C) C₆H₈
D) C₆H₉Cl
E) none of these