Consider the reaction $\mathrm{aX} \rightarrow \mathrm{bY}$, for which the rate constant at $30^{\circ} \mathrm{C}$ is $1 \times 10^{-3} \mathrm{~mol}^{-1} \mathrm{Ls}^{-1}$. Which of the following statements are true? A. When concentration of ' $X^{\prime}$ ' is increased to four times, the rate of reaction becomes 16 times. B. The reaction is a second order reaction. C. The half-life period is independent of the concentration of $X$. D. Decomposition of $\mathrm{N}_2 \mathrm{O}_5$ is an example of the above reaction. Choose the correct answer from the options given below :