[单选题]
An object is moving wit1 6rgpe0glo9k-ojfd )h/u 7do,a ec/ng constant non-zero acceleration in the +x axis. The velocity versusndecag ,//ou7 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.
