When a primary alcohol is oxidized, the alcohol functional group (-OH) is converted into a carboxylic acid functional group (-COOH). The general formula for a primary alcohol is R-OH, where R is an alkyl group. The oxidation of a primary alcohol can be represented as follows:

R-CH2-OH + [O] → R-COOH + H2O

In this case, the alcohol has the molecular formula C4H10O, which suggests that it is a primary alcohol. The oxidation of this alcohol will therefore produce a carboxylic acid with the molecular formula C4H8O2.

Therefore, the correct answer is C: C4H8O2.