Task: Question Answering
Input (English): Problem: two trains a and b starting from two points and travelling in opposite directions , reach their destinations 9 hours and 4 hours respectively after meeting each other . if the train a travels at 60 kmph , find the rate at which the train b runs . 
Options: a ) 40 , b ) 60 , c ) 120 , d ) 90 , e ) 100
Output (English): d