An endothermic reaction needs energy to occur because Reactants need more energy to break bonds than is produced from making new bonds in products.
Hence, the correct answer is B.
Here is an explanation :
An endothermic reaction is a chemical reaction that requires energy to be absorbed for the reaction to occur.
In an endothermic reaction, the products have more energy than the reactants supplied by the surroundings (usually in heat). For the reactants to turn into products, the bonds between atoms in the reactants must be broken, and new bonds must be formed between the atoms to make the products.
The breaking of bonds requires energy, while the formation of new bonds releases energy. In an endothermic reaction, the energy required to break the bonds in the reactants is greater than the energy released from forming new bonds in the products.
Therefore,
the reactants need more energy to start the reaction than is produced from making new bonds in the products.