Answer:
B
Step-by-step explanation:
At significantly higher temperatures, the rate of an enzyme-catalyzed reaction decreases because the shape of the enzyme changes at high temperatures. Enzymes are proteinous in nature, and as such, are generally sensitive to high temperatures.
They simply become denatured by high temperatures. In other words, they lose their original shape and their catalyzing abilities as the temperature gets progressively high during the course of reactions, thus, decreasing the rate of a reaction.
The correct option is, therefore, B.