Villagers in some parts of India use the water extract of the ash obtained by burning banana plant as a substitute of soda. Which one of the following is the major active component in the extract ?

Plants absorb minerals from the soil, including potassium, sodium, calcium, and magnesium. When plant material is burned, the organic components are removed, leaving behind the mineral residues, primarily as carbonates or oxides. Banana plants are known to accumulate significant amounts of potassium. Burning plant material rich in potassium leads to the formation of potassium carbonate (K₂CO₃). This alkali compound, when extracted with water, yields a solution of potassium carbonate, which has alkaline properties similar to soda (sodium carbonate or sodium bicarbonate).