单项选择题

一肥料包装袋上印有12-12-12,表明该肥料含有( )
A. 12%N,12%P2O5,12%K2O
B.12%N,12%P,12%K
C. 12 N:12 P2O5:12 K2O
D.12%N2O,12% P2O5 ,12% K2O

A.12%N,12%P,12%K
B.12%N2O,12%