Answer the following question given this paragraph: 

After equilibrium has been reached, the concentrations of all reaction components will remain constant unless a change is made to the system. Because the concentrations are no longer changing, it may appear that the reaction has "stopped. " This is incorrect; both the forward and reverse reactions are still going on, even at equilibrium. However, because the two reactions are proceeding at the same rate, no net change is observed.


Q: After what state is reached, the concentrations of all reaction components remain constant unless a change is made to the system?

 Choices:

- homeostasis

- level

- equality

- equilibrium

A:
equilibrium
