Which one of the following groups of chemical compounds is composed entirely of organic compounds? A. C 2 H 2 , CH 4 , CaCl 2 , CaCN 2 B. C6H6, C2H5OH, C6H5CH3, C3H5(NO3)3 C. C 2 H 4 O, CH 2 O, CaSO 4 , C 3 H 5 (OH) 3 D. Ch3OCH3, Ca3(PO4)2, CO2, H2CO3