Which of the following statements about fertilisers is correct?
- AAmmonium sulfate, $(\text{NH}_4)_2\text{SO}_4$, is a better fertiliser than ammonium nitrate, $\text{NH}_4\text{NO}_3$, because it contains more oxygen.
- BAmmonium phosphate, $(\text{NH}_4)_3\text{PO}_4$, is a good fertiliser because it contains hydrogen.
- CPotassium nitrate, $\text{KNO}_3$, is a good fertiliser because it provides potassium and nitrogen.
- DUrea, $(\text{NH}_2)_2\text{CO}$, is a good fertiliser because it contains carbon.