Answer:
The equilirbium shifts to side where the reactant is lowered so that the reactant comes back to normal level for equilibrium.
Explanation:
This is the basic premise of Le Chatelier's principle which can be used to predict the effect of a change in conditions on some chemical equilibria.
If A--->B is at equiblirum and if concentration of A goes down, then the equilirbium shifts left to make more A.
