Question

Why formation of ozone hole is maximum at antarctica?

Answer 1

because of chloro floro carbon

Answer 2

Despite not having any significant source , the abundance of CFC in Antarctica is quite high.  

That’s because of Atmospheric mixing. CFC’s are very stable molecules- so stable that they survive to reach the highest levels of the atmosphere, and remotest corner of the globe- the Antarctica. It’s not that only Antarctica have abundance of CFC’s.