Given the task definition and input, reply with output. 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'.

Problem: train a leaves the station traveling at 30 miles per hour . two hours later train leaves the same station traveling in the same direction at 42 miles per hour . how many miles from the station was train a overtaken by train b ?
Options: a ) 150 , b ) 170 , c ) 190 , d ) 210 , e ) 230
d