Answer: The correct answer is Option 2.
Step-by-step explanation:
Reversible reaction is defined as the reaction in which the products formed react together to give the reactants back. For general reversible chemical equation:

At equilibrium, the rate of forward reaction is equal to the rate of backward reaction.
Rate of forward reaction:
![k[A]^a[B]^b](https://img.qammunity.org/2015/formulas/chemistry/middle-school/6xmk39stp2z4l452jpotqg9i6175fqkjag.png)
Rate of backward reaction:
![k[C]^c[D]^d](https://img.qammunity.org/2015/formulas/chemistry/middle-school/okiyk3qd24ipvzmrx4lihvrp0t6wo0ki0n.png)
At equilibrium,
=
![k[C]^c[D]^d](https://img.qammunity.org/2015/formulas/chemistry/middle-school/okiyk3qd24ipvzmrx4lihvrp0t6wo0ki0n.png)
Thus, the correct answer is Option 2.