What is the IUPAC name for the molecular formula C4H10O?

The molecular formula C4H10O corresponds to an alcohol, specifically a four-carbon alcohol. In IUPAC nomenclature, alcohols are named by identifying the longest carbon chain containing the hydroxyl group (-OH), and the suffix "-ol" is added to the name of the corresponding alkane.

For a compound with four carbon atoms, the base name is "butane." Since it contains an -OH group, the appropriate suffix transforms it to "butanol." The positioning of the hydroxyl group might dictate the specific isomer of butanol, but without additional structural information, the simplest and most inclusive name is butanol.

Other options listed do not match the characteristics defined by the formula. Butyne describes an alkyne, Cyclobutane refers to a cyclic alkane, and Butyric acid denotes a carboxylic acid, none of which align with the presence of an alcohol functional group as indicated by the formula C4H10O. Thus, the correct answer is butanol.