The true statement for the acids of phosphorus, H₃PO₂, H₃PO₃ and H₃PO₄ is

The geometry of all the 3 4 3 3 3 2 , , H PO H PO H PO is shown in the following figure- H P O OH H HO P O O H P O OH H O P OH OH P OH O OH H O P OH O OH O P OH OH P OH O OH 9 P-BLOCK ELEMENTS (GROUP 15-18) 3 4 H PO is a tribasic acid, 3 3 H PO is a dibasic acid and 3 2 H PO is a monobasic acid. When number of OH increases, the acidity also increases. Thus, the order is- 3 4 3 3 3 2 H PO H PO H PO The geometry of all these acids are not tetrahedral and phosphoric acid 3 4 H PO is the strongest reducing agent. Thus, the correct option is-(a)