The unit of the velocity constant in case of zero order reaction is

$A$ zero-order reaction,$A \rightarrow \text{Product}$,with an initial concentration $[A]_0$ has a half-life of $0.2 \ s$. If one starts with the concentration $2[A]_0$,then the half-life is $.... \ s$

Decomposition of $X$ exhibits a rate constant of $0.05 \ \mu g/year$. How many years are required for the decomposition of $5 \ \mu g$ of $X$ into $2.5 \ \mu g$?

Which of the following equations represents the integrated rate law for a zero order reaction?

Consider the reaction $aX \to bY$, for which the rate constant at $30^\circ C$ is $1 \times 10^{-3} \text{ mol L}^{-1} \text{ s}^{-1}$. Which of the following statements are true?
$A$. When concentration of $X$ 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 $N_2O_5$ is an example of the above reaction.
$E$. $\ln \frac{[R]_0}{[R]}$ vs time is valid for the above reaction.

Which among the following reactions is an example of a zero-order reaction?