Task: Question Answering
Input (English): Question: Lamp A flashes every 6 seconds, Lamp B flashes every 8 seconds, Lamp C flashes every 10 seconds. At a certain instant of time all three lamps flash simultaneously. During the period of 4 minutes after that how many times will exactly two lamps flash? (Please include any flash of exactly two lights which occurs at the 4 minute mark.)

 Option A: 16

 Option B: 17

 Option C: 18

 Option D: 19

 Option E: 20
Output (English): Option C