Read the Passage carefully and answer the Questions.

Kinetic studies not only help us to determine the rate of a chemical reaction but also describe the conditions by which the reaction rates can be altered. The factors such as concentration, temperature, pressure and catalyst affect the rate of a reaction. The speed of a reaction or the rate of a reaction can be defined as the change in concentration of a reactant or product in unit time.

Rate = $k [A]^x [B]^y$

Here k is the rate constant

$x + y$ gives the overall order of a reaction, whereas x and y represent the order with respect to the reactants A and B, respectively. 

The order of a reaction which does not exist is

Pseudo second order reaction

The correct answer is Option (4) → Pseudo second order reaction

Zero order reaction: This exists. The rate of the reaction is independent of the concentration of the reactant(s). Example: decomposition of ammonia ($\text{NH}_3$) on a hot platinum surface.

First order reaction: This exists. The rate of the reaction is proportional to the first power of the concentration of one reactant. Example: decomposition of dinitrogen pentoxide ($\text{N}_2\text{O}_5$).

Pseudo first order reaction: This exists. It is a second-order reaction whose rate law can be simplified to first order because one of the reactants is present in a large excess, making its concentration effectively constant during the reaction. Example: hydrolysis of an ester catalyzed by acid.

Pseudo second order reaction: This term is not a standard, recognized classification for reaction order in chemical kinetics. Reaction orders are typically defined as zero, first, second, third, fractional, or pseudo first order.