A, in Figure A, distance is proportional to time, indicating that A moves in a straight line at a constant speed, while in Figure B, the ratio of distance to time becomes smaller, indicating that A is incorrect;

B, according to the image: in the first 6 seconds, sA=0.4m, sB=0.6m, so according to v=st, it can be seen that the average speed of goods A is less than that of goods B, so B is correct;

C and A goods move in a straight line at a uniform speed, and gravity and the tension of wire rope on it are a pair of balancing forces, which are equal in size, so C is incorrect;

Goods D and B are not in uniform linear motion or static state, so gravity and traction of steel wire rope are not a pair of balancing forces, so D is incorrect.

So choose B.