What is the first action to take with a flat tire while riding?

Answer: B — Hold handlegrips firmly

When a rider experiences a flat tire, the first and most crucial action is to hold the handlegrips firmly. This is important because a flat tire can cause the motorcycle to become unstable, especially if it occurs while in motion. By maintaining a strong grip on the handlegrips, the rider can better control the motorcycle and stabilize it, thereby reducing the risk of losing control or crashing. The other options might suggest actions that could lead to a loss of control or add to the danger during this critical moment. For example, pulling the throttle could increase speed and worsen the instability caused by the flat tire, while shutting off the engine may disrupt bike handling. Leaning to one side could further compromise stability and control. Therefore, maintaining a firm grasp is essential for safety in this situation.