Both B and C look about the same on my computer.
B seems to have a bit more occasional "tearing" where the top and the bottom dont' line up.
i thought that might be because of the mismatch between 25fps and my 60 fps monitor, but C doesn't seem to have the tearing as much as B played on the same monitor. I have both an LCD and a CRT
I don't think PCs wait for a screen redraw to start before it displays a new frame of video so that may account for the tearing in images that is visible in horizontally moving objects. The mismatch between 25fps and 60 fps would probably create quite a few split frames.
However if I step thru either one frame by frame, the car appears to move the same amount in each frame so at least it's not A:M that is the problem.
The gif runs rather slowly on my computer so the stepping from frame to frame is very obvious in that one.