Which of the following is not done by Bo Le to train the horses?
A．He brands them with a hot iron, trims their manes, cuts their hoofs, and puts halters on their heads
B．He ties up the horses with the halter on their heads and ropes on their legs, makes them stand up in a row in the stable
C．He trains them to run as fast as possible on different lands such as streets, grasslands, deserts, and mountains
D．He trains them to run together at the same pace by keeping before them the fear of snaffles and ropes, behind them the fear of whips