Answer and explanation:
The attached figure shows five different structures for the chemical formula C4H5O5, but only one of these structures represent the malic acid.
Malic acid is a dicarboxylic acid, this means malic acid has two
-COOH groups. Also, malic acid is a secundary alcohol, which means it has a R2-C-OH group.
-Structure A has two carboxylic groups, but it doesn´t have a secundary alcohol.
-Structure B doesn´t have any caborxylic group.
-Structure C has two carboxylic groups and it is a secundary alcohol. Structure C is the Malic acid