a compound of molecular formula c5h12o2 compound has strong infrared absorption at 3300 to 3400 cm. its 1h-nmr spectrum has three singlets at 0.9, 3.45, and 3.2 ppm; relative integrals at 3:2:1. the 13C-NMR spectrum shows three signals all at higher field than 100 ppm. which of the following compounds best fits this data?