An equimolar mixture of X (g) and Y (g) is placed inside a rigid container at constant temperature. The particle diagram above represents the changes that occur over time. Based on the particle diagram, which of the following best predicts whether or not the system has reached equilibrium by 300 s?
a. It is not possible to determine that the system has reached equilibrium by 300 s because the stoichiometry of the reaction is not known.

b. it is not possible to determine that the system has reached equilibrium by 300 s because the amounts of X, Y, and XY have continued to change

c. The system has reached equilibrium by 300 s because the rate of formation of XY is constant
d. The system has reached equilibrium by 300 s because the rates of consumption of X and Y are equal