Which of the following is the incorrect equation for the rate constant of a zero-order reaction?

For a reaction $A \rightarrow$ products,the half-life period is $1 \ h$. The initial concentration of reactant $A$ is $2 \ M$. If this reaction is of zero order,how many hours will it take for the concentration of the reactant to decrease from $0.5 \ M$ to $0.25 \ M$?

Which of the following is correct with respect to the graph given?
$\begin{aligned} & [R]=\text{Concentration at time } t \\ & [R]_0=\text{Initial concentration} \end{aligned}$

Time required for $100\%$ completion of a zero order reaction is

When a graph of concentration $\rightarrow$ Time is plotted for a zero order reaction,the value of the slope is . . . . . . .

The rate of a certain reaction depends on concentration according to the equation $-dc/dt = (K_1 C) / (1 + K_2 C)$. What is the order when concentration $(C)$ is very high?