Select the correct statement(s).

A) As $k=A{e}^{(-E_a/RT)}$, so it will be equal to A when $T⟶\infty$ or $E_a⟶0$.
B) Catalyst never changes the overall energy of a reaction.
C) A reaction can be thermodynamically unstable but kinetically stable because the conditions are such that the rate of the reaction is zero. A mixture of coal and oxygen are kinetically stable because the condition for combustion are not obtained until the coal is heated to its ignition temperature. The system is thermodynamically unstable because at equilibrium the coal oxygen reaction favors the formation of $C{O}_2$.
D) A negative catalyst increases the activation energy of the reaction and slows down the rate of reaction.