This graph shows the activation energy required for a certain biochemical reaction to take place. The effect of an enzyme on the same biochemical reaction is shown by

Hint: Enzymes are the constituents of the various amino acids and may change due to various physical conditions. They are helpful in various functions of the body that include growth and development, reproduction, and various life processes.

Complete answer:
Enzymes are major proteins and some exist in RNA form, which is known as the catalytic RNAs or ribozymes, but no enzymes exist in lipid form. The proteins are the most important biomolecules found in the enzyme. The enzyme’s activity, functioning, and potential may vary due to several factors that include both the chemical and the physical factors. These factors include pH, temperature, etc. The proteins are responsible for the increase in the activation energy of the enzymes and results in the formation of the substrate. The activation energy is the minimum or least amount of energy that is required by all enzymes to undergo any biochemical reaction.
Enzymes are the macromolecular natural catalysts. These are profoundly particular catalysts significantly quickening both the rate and explicitness of metabolic reactions. Enzymes are incredibly effective and have extraordinary catalytic power, changing around 100 to 10,000 substrate molecules into product every second and continuing from 103 to 108 to multiple times quicker than the uncatalyzed reaction. They increase the rate of reaction and lower the activation energy, thus they are called the biological catalysts. Enzymes don’t affect the equilibrium constant notwithstanding the increase in the conversion rate of the substrate into the product. The energies of the original reactants and products remain the same.

So, the correct answer is ‘C’.

Note:
The enzyme was first discovered in 1833 by the French chemist Anselme Payen. Diastase was the first enzyme to be discovered. The specific enzyme action with one substrate was first explained in 1894 through the lock and key theory by Emil Fischer where the enzyme represents the lock while the substrate represents the key.