The correct answer is: A. 10 kmph.
When the driver reports rough running or lurch on the run, the SM to issue caution order with speed 10 kmph. This is because rough running or lurch on the run can be caused by a number of problems, including engine misfire, fuel starvation, and transmission problems. These problems can cause the vehicle to lose power and control, which can be dangerous at high speeds. By issuing a caution order with speed 10 kmph, the SM is ensuring that the driver is driving at a safe speed and that they have time to react to any problems that may occur.
Option B, 15 kmph, is incorrect because it is not a safe speed to drive at if the vehicle is experiencing rough running or lurch on the run. Option C, 20 kmph, is also incorrect for the same reason. Option D, None of these, is incorrect because it is not a valid option.