Which of the following is known as Indian salt petre?

Nitrogen is readily available in the atmosphere, although it is far less common $\left(1.9\times {10}^{-3}\mathrm{\%}\right)$ in the earth's crustal rocks and soils. It occurs as sodium nitrate ${\mathrm{NaNO}}_3$ (also known as Chile saltpetre) and potassium nitrate ${\mathrm{KNO}}_3$ in the earth's crust (called indian saltpreter)