A man covered a certain distance at some speed. Had he moved 3 kmph faster, he would have taken 40 minutes less. If he had moved 2 kmph slower, he would have taken 40 minutes more. The distance (in km) is :
Options:
 A. $$35$$ km B. $$36\frac{2}{3}$$ km C. $$37\frac{1}{2}$$ km D. $$40$$ km