The answer is B. The complete equation is C6H12O6 + 6O2 -->6H2O + 6CO2 + energy. So we can know that A and C and D is right. For B, the reaction release energy so it is exothermic reaction.
This reaction involves glucose and oxygen as reactants on left hand side and water, carbon dioxide and energy as products on right hand side.
The chemical equation shows law of conservation of mass, which means equal number of atoms of each element are present on both sides of the arrow. Thus 18 atoms of oxygen are present on both sides of the arrow.
The reaction releases energy and thus is a exothermic reaction. The reaction which absorbs energy is called as endothermic reaction.
