In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

Although not a primary alcohol, only one of these compounds with a methyl group undergoes the iodoform reaction. Their simplest example is mixed with sulfuric acid to form Marquis' reagent, which can be used to identify alkaloids. LDA usually cannot be used to deprotonate these compounds to form enolates because self-condensation is too fast. These compounds are transformed into an alkyne by the Corey-Fuchs reaction. When these compounds lack an alpha-hydrogen, they can undergo disproportionation to yield an alcohol and a salt of a carboxylic acid in the Cannizzaro reaction. Unlike a similar organic compound, they have reducing properties, which results in their oxidation in Tollens' reagent, creating a silver mirror. That mirror distinguishes them from ketones. For 10 points, identify these compounds that contain a formyl group and whose simplest example has chemical formula CH2O.
Science