Time taken to complete a zero order reaction is . . . . . . .

Which of the following plots is correct for a zero-order reaction?

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?

For a zero order reaction,the plot of concentration $(a - x)$ $vs$ time is linear with

What is the unit of $K$ for a zero-order reaction?

What is the unit for the zero order rate constant?