Which soil ameliorants are used in sodic soil reclamation that is cheaper and easily available?

Correct option is A

Gypsum (option a) is commonly used as a soil ameliorant in sodic soil reclamation due to its effectiveness in reducing soil sodium levels. It is a cost effective and readily available option. Gypsum works by promoting the displacement of sodium from soil particles, improving soil structure and permeability. Other options like ammonium sulfate, lime, iron pyrite, and ammonium nitrate may not be as suitable or cost effective for sodic soil reclamation.