单项选择题

一平面简谐波表达式为y=-0.05sinπ(t-2x)(SI),则该波的频率v(Hz),波速u(m/s)及波线上各点振动的振幅A(m)依次为()。

A.1/2,1/2,-0.05
B.1/2,1,-0.05
C.1/2,1/2,0.05
D.2,2,0.05