The correct option is C In a dynamic equilibrium, the reaction stops
(a) True
As the flask is insulated, the amount will remain same and equilibrium will be established (as the container is closed).
(b) True
At equilibrium there is no change in the concentration of either the reactants or the products.
(c) False
In a dynamic equilibrium, reactions continue to occur and does not stop. It is just that the concentration of reactants and products are not changing with time and the rate of forward reaction is equal to the rate of backward reaction.
(d) True
In a irreversible reaction, the reaction proceeds in one direction only. Whereas equilibrium can only be established if the reaction is reversible.