The slowest step of a reaction mechanism is called the
a.) elementary step
b.) inhibitor
c.) rate law
d.) rate-determining step

D.) Rate-Determining Step

Explanation:

Rate - Determining Step -

The slowest step of any of the chemical reaction helps to find the overall rate of the chemical reaction , and , hence is known as the rate - determining step .

There are two type of reaction possible , one is elementary reaction and a complex reaction .

Elementary reaction is a single step reaction , and hence , that very step determined the rate of the reaction and hence is known as the rate determining step .

And ,

In case of a complex reaction , the reaction is preceded by many steps , and hence , the slowest step among other steps is known as the rate determining step of the reaction .