Complete combustion of 2.04 g of a liquid hydrocarbon yields 6.60 g of carbon dioxide. What is the empirical formula of this hydrocarbon?
CH2\text{CH}_2CH2
C2H3\text{C}_2\text{H}_3C2H3
C3H5\text{C}_3\text{H}_5C3H5
C5H8\text{C}_5\text{H}_8C5H8