Answer: -
Solubility of a substance depend on the balance of intermolecular forces between the solvent and solute, and the entropy change that accompanies this process.
Temperature and pressure also plays a role in solubility.
A solution having Group 1 cations like lithium, sodium, potassium etc are always soluble.
A solution having NH₄⁺ is soluble.
All salts with anion as nitrates, acetates, chlorates, and perchlorates are soluble in water.
Answer : The equilibrium will shift in the left direction.
Explanation :
Le-Chatelier's principle : This principle states that if any change in the variables of the reaction, the equilibrium will shift in the direction to minimize the effect.
The given reaction is:

As per question, when we are adding
then the concentration of
is increased on product side then the equilibrium will shift in the direction where decrease of concentration of
takes place. Therefore, the equilibrium will shift in the left direction.
Thus, the equilibrium will shift in the left direction.
The periodic table increases as you read left to right so it is A.