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: a , b and c run around a circular track starting from the same point simultaneously and in the same direction at speeds of 4 kmph , 6 kmph and 8 kmph respectively . if the length of the track is 400 meters , when will a , b and c meet at the starting point for the first time after they started the race ?
Options: a ) 1 minute , b ) 5 minutes , c ) 12 minutes , d ) 20 minutes , e ) 24 minutes
c