$2\mathrm{A}$ $\to$ $\mathrm{B}$ $+$ $\mathrm{C}$; It would be a zero-order reaction when:

If the rate of the reaction is equal to the rate constant, the order of the reaction is:

The rate of reaction between two reactants A and B decreases by a factor of 4 if the concentration of reactant B is doubled. The order of this reaction with respect to reactant B is:

1. 2

2. –1

3. 1

4. –2