`A ,\ B` and `C` start at the same time in the same direction to run around a circular stadium. A completes a round in 252 seconds, `B` in 308 seconds and `C` in 198 seconds, all starting at the same point. After what time will they meet again at the starting point? (a) 26 minutes 18 seconds (b) 42 minutes 36 seconds (c) 45 minutes (d) 46 minutes 12 seconds