[单选题]
An object is moving with constand2e+(v qfz5 out non-rl8as0cifv 3p 6le41 uwk 6j3jzero acceleration in the +x axis. The velocity ver 1 u3 lri384ajclfw60ke6psjvsus 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.