The rate of a reaction $A \rightarrow B$ is $0.2 \mathrm{~mol} \mathrm{~m}^{-3} \mathrm{~s}^{-1}$ at a particular concentration $C_{A 1}$. The rate constant of the reaction at a given temperature is $0.1 \mathrm{~m}^{3} \mathrm{~mol}^{-1} \mathrm{~s}^{-1}$. If the reactant concentration is increased to $10 C_{A 1}$ at the same temperature, the reaction rate, in $\mathrm{mol} \mathrm{m}^{-3} \mathrm{~s}^{-1}$, is
- $20$
- $10$
- $100$
- $50$