Give the characteristic of a first order reaction having only one reactant.
a) the rate of the reaction is proportional to the square root of the concentration of the reactant.
b) the rate of the reaction is directly proportional to the concentration of the reactant.
c) the rate of the reaction is not proportional to the concentration of the reactant.
d) the rate of the reaction is proportional to the square of the concentration of the reactant.
e) the rate of the reaction is proportional to the natural logarithm of the concentration of the reactant.