Answer: Option (A) is the correct answer.
Explanation:
A chemical reaction where heat energy is absorbed by the reactant molecules is known as an endothermic reaction.
For example, [tex]A + B + Heat \rightarrow AB[/tex]
The value of [tex]\Delta H[/tex] = +ve for an endothermic reaction.
In an endothermic reaction, more heat is absorbed by the chemical bonds for the breakdown as compared to the heat released.
On the other hand, a chemical reaction in which heat energy is released by the reactant molecules is known as an exothermic reaction.
For example, [tex]C + D \rightarrow CD + Heat[/tex] is an exothermic reaction.
Thus, we can conclude that endothermic reaction is the type of reaction which is represented by A.