As you increase the temperature of an enzyme-catalyzed reaction, the rate of the reaction initially increases. it then reaches a maximum rate and finally dramatically declines. keeping in mind that enzymes are proteins, how do you explain these changes in reaction rates?

a. at first the reaction rate increases because the temperature increase causes the enzyme to denature. at some point the rate of reaction dramatically decreases because the enzyme and substrate collisions increase.
b. at first the rate of reaction increases because the temperature increase causes a decrease in the number of collisions between the enzyme and the substrate. at some point the rate of reaction dramatically decreases because the enzyme denatures due to the high temperature.
c. at first the reaction rate increases because the temperature increase causes the enzyme to coagulate. at some point the rate of reaction dramatically decreases because the enzyme and substrate collisions increase.
d. at first the rate of reaction increases because the temperature increase causes an increase in the number of collisions between the enzyme and the substrate. at some point the rate of reaction dramatically decreases because the enzyme denatures due to the high temperature.