A hard stop. You need to let the motorbike pick up speed, but not too much, and try to brake hard
When riding your motorbike on dirt or wet roads, use primarily the rear brake to manoeuvre. On pavement, on the contrary, use the front brake. This enables you to reduce the braking distance, if we compare it with the rear brake performance. However, remember that you need to steer the vehicle and not tightly cling to the handlebars to the last. This could easily lead to you flying over the motorbike. For mopeds, due to the different distribution of the center of gravity, it is more efficient to use the rear brake. It is training practice that will help you understand which brake should be used and in which cases.