Pls solve step by ,step B option is answer

**10 In a traffic accident, a car leaves skid marks of 20 m long on the road during sudden braking. Investigators find that the same car travelling at 50 km ho leaves skid marks of 10 m long during sudden braking. Assume that the car brakes at the same constant deceleration in both cases. Estimate the speed of the car just before braking in the accident. A 19.6 km h- B 70.7 km h- C 75 km h-1 D 100 km h- Refer p.64