W(N)={2M(N)/M(NH₄NO₃)}*100%
w(N)={2*14.0 g/mol/80.0 g/mol}*100% = 35%
Answer: The correct option is A.
Explanation: In a chemical reaction, reactants react to form a number of products.
For the formation of products, the bonds of the individual reactants must be broken and the bonds of the products must be formed.
For example: Formation of water from hydrogen gas and oxygen gas. Reaction follows:

The Bonds of hydrogen and oxygen molecule are broken and new bonds between hydrogen and oxygen atoms are formed to give water molecule.
Condensation occurs through the release of energy
Decomposition,because 1 breaks down into 2