Task: Question Answering
Input (English): Question: Two trains run in opposite directions on a circular track. Train A travels at a rate of 4π miles per hour and Train B runs at a rate of 6π miles per hour. If the track has a radius of 6 miles and the trains both start from Point T at the same time, how long, in hours, after the trains depart will they again meet at Point T?

 Option A: 3

 Option B: 6

 Option C: 9

 Option D: 18

 Option E: 22
Output (English): Option B