Which of the following statements is true regarding potassium chloride and potassium sulfate?

The correct option is Both are obtained by mining. This answer is correct because it matches the approved learning objective to recall that potassium chloride and potassium sulfate are obtained by mining. (Chemistry only) in the subtopic Production and uses of NPK fertilisers.

The correct option is Both are obtained by mining. Both are obtained by mining is correct because it directly supports the approved learning objective to recall that potassium chloride and potassium sulfate are obtained by mining. (Chemistry only). This belongs to the subtopic Production and uses of NPK fertilisers within The Haber process and the use of NPK fertilisers, so the explanation must stay tied to that curriculum context. The other options are incorrect because they either do not answer this learning objective, use a vague statement, or move away from Production and uses of NPK fertilisers.