[单选题]
An object is moving with constant non -ow uru/t1v.x-zero acceleration in the +kcj s lcd.8z82mji*alr2 f(+px axis. The positionm+8cj*s 8dkiz2 .afcj2(rl p l versus time graph of this object is
A. a horizontal straight line.
B. a vertical straight line.
C. a straight line making an angle with the time axis.
D. a parabolic curve.