Which one of the following given graphs represents the variation of rate constant (k) with temperature (T) for an endothermic reaction?

For a reaction of order n, the unit of the rate constant is :

For the following graphs,


Choose from the options given below, the correct one regarding order of reaction is :

Isotope(s) of hydrogen which emits low energy $$\beta$$^$$-$$ particles with t_1/2 value > 12 years is/are