Oxyacid having P-H bond can reduce \(AgNO_3\) to \(Ag\).
So, the correct option is (D): \(H_4P_2O_5\).
The method that is based on the difference in oxidation number of oxidizing agent and the reducing agent is known as oxidation number. The half-reaction method entirely depends on the division of the redox reactions into oxidation half and reduction half. It entirely depends on the individual which method to choose and use.
Like various other reactions, it is very important to write the correct compositions and formulas. A very important thing to keep in mind while writing oxidation-reduction reactions is to write the compositions and formulas of the substances and the products present in the chemical reaction in a very correct manner.
In this procedure, we decouple the equation into two halves. After that, we balance both the parts of the reaction separately. Finally, we add them together to get a balanced equation.