The functional groups in an organic compound can frequently be deduced from its infrared absorption spectrum. A C6 hydrocarbon exhibits bands between 3000-3100 (w), 2850-2960 (m), and at 1650 cm-1 (w). Relative absorption intensity: (s)=strong, (m)=medium, (w)=weak. What functional class(es) does the compound belong to? List only classes for which evidence is given here. Attach no significance to evidence not cited explicitly. Do not over-interpret exact absorption band positions. None of your inferences should depend on small differences like 10 to 20 cm-1.