Which of the following distinguishes the composition of a fertilizer with the label marked 15-10-25?
A. 15% nitrogen, 10% phosphorus, 25% potassium
B. 15% phosphorus, 10% nitrogen, 25% potassium
C. 15% potassium, 10% phosphorus, 25% nitrogen
D. 15% nitrogen, 10% potassium, 25% phosphorus