Task: Question Answering
Input (English): Problem: yesterday it took robert 4 hours to drive from city a to city b . today it took robert 2.5 hours to drive back from city в to city a along the same route . if he had saved 15 minutes in both trips , the speed for the round trip would be 70 miles per hour . what is the distance between city a and city b ? 
Options: a ) 90 , b ) 120 , c ) 150 , d ) 210 , e ) 300
Output (English): d