Answer:
Option B. The equilibrium of the reaction would shift to the right.
Explanation:
According to Le Chatelier's principle, when an external constrain such as change in concentration, temperature or pressure is imposed on a chemical system in equilibrium, the equilibrium position will shift in order to neutralize the effect.
Now, let us answer the question above.
From the question given above, the equation is:
A + B <===> C + D
Increasing the concentration of A will shift the equilibrium position to the right.
This is true because increasing the concentration of A means having more reactants in the system. So the reactants react to produce more product thereby shifting the equilibrium position to the right.