Red # 11 is supposed to choose the possibility B.

Photo of the question

Both of the red cars have not yet made a pit stop. Red # 12, who is at the end of the 4th lap, now has the last opportunity to drive into the pit lane, whereas Red # 11 can do it a lap later on.

Red # 12 is on a square without speed limit. If the track is not blocked, he is forced to drive with two dice. So most likely he will roll more than six. At a speed above he is not allowed to drive into the pit lane, and hence would fail to enter the pit lane, then. In this case Red # 12 would get the red handicap-flap (Rules: Pit Stop), when passing the finish line.

If Red # 11 will assure his team mate to enter the pit lane, he has to achieve a blocking of the track with less than 12 squares for Red # 12 to go. If Red # 11 moves to the square B there are only 11 squares for his team mate to go. Hence Red # 12 is allowed to roll only with one die instead of two, and so surely can enter the pit lane.