Definition: In this task, you need to answer the given multiple-choice question on the physics. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.
Input: Problem: a train crosses a bridge of length 1500 m in 70 seconds and a lamp post on the bridge in 20 seconds . what is the length of the train in metres ?
Options: a ) 375 m , b ) 750 m , c ) 250 m , d ) 600 m , e ) 300 m
Output:
d