Need Chemistry help ASAP! Which of the following statements regarding chemical equilibrium is NOT necessarily true?

A.) Equilibrium is shown using a double arrow.
B.) When a system is at equilibrium, it continues to react both ways (forward and reverse).
C.) At equilibrium, the amounts of reactants equal the amounts of products. D.) At equilibrium, particle-level changes are occurring.

Need an answer as soon as possible! Thanks so much!