由图象可直接求出车的速度 v甲= s甲 t甲 = 2.4m 6s =0.4m/s,v乙= s乙 t乙 = 1.2m 12s =0.1m/s,由此可知V甲>V乙,故C、D错误.经过6秒,甲车路程s甲=2.4m,乙车路程s乙=0.6m,因甲、乙两小车同时同地反方向做匀速直线运动,所以两车之间的距离为2.4m+0.6m=3.0m.故A错误,B正确.故选B.