Which of the following is a product of the reaction between phosphate rock and phosphoric acid?

The correct option is Soluble phosphate salts. This answer is correct because it matches the approved learning objective to describe treatment of phosphate rock with phosphoric acid to produce soluble salts for fertilisers. (Chemistry only) in the subtopic Production and uses of NPK fertilisers.

The correct option is Soluble phosphate salts. Soluble phosphate salts is correct because it directly supports the approved learning objective to describe treatment of phosphate rock with phosphoric acid to produce soluble salts for fertilisers. (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.