What is the relationship between the half-life period $(t_{1/2})$ and the initial concentration $([R]_0)$ for a reaction of order $n$?

Which one of the following statements regarding the order of a reaction is not correct?

What is the order of reaction if the unit of the rate constant is $s^{-1}$?

$A$ reaction is first order in terms of $A$ and second order in terms of $B$. What will be the rate of reaction,if the concentration of $B$ is increased two times?

Define the following terms:
$(1)$ Elementary reaction
$(2)$ Complex reaction

The following data is given for the reaction between $A$ and $B$:

$S.NO.$	$[A] \ mol \ L^{-1}$	$[B] \ mol \ L^{-1}$	$Rate \ mol \ L^{-1} \ sec^{-1}$
$I$	$1 \times 10^{-2}$	$2 \times 10^{-2}$	$2 \times 10^{-4}$
$II$	$2 \times 10^{-2}$	$2 \times 10^{-2}$	$4 \times 10^{-4}$
$III$	$2 \times 10^{-2}$	$4 \times 10^{-2}$	$8 \times 10^{-4}$

Which of the following are correct statements?
$(a)$ Rate constant of the reaction is $1 \ mol^{-1} \ L \ sec^{-1}$.
$(b)$ Rate law of the reaction is $k[A][B]$.
$(c)$ Rate of reaction increases four times on doubling the concentration of both the reactants.