Reclamation of alkali soils can be done by using?

Correct option is A

The reclamation of alkali soils can be achieved by using gypsum (calcium sulfate). Gypsum is effective in improving soil structure and drainage by displacing sodium ions, which are responsible for soil alkalinization. The calcium in gypsum replaces sodium, leading to the formation of calcium-sodium aggregates that enhance soil permeability and reduce the adverse effects of soil alkalinity on plant growth.