Task: Question Answering
Input (English): Problem: a software engineer starts from home at 3 pm for every walk on a route which has level road for some distance and a then a hillock . he walks speed of 4 kmph on level ground and then at a speed of 3 kmph on the uphill and then down the hill at a speed of 6 kmph to the level ground and then at a speed of 4 kmph to the home if he reaches home at 9 pm . what is the distance one way of his route ? 
Options: a ) 12 km , b ) 15 km , c ) 18 km , d ) 24 km , e ) data inadequate
Output (English): a