Re: Which exchanges are the best for selling puts and calls options on Bitcoin?
Binance is one of the right choices for you friends because it already provides many features and transactions that are safe and very fast. as of now binance is the number one crypto exchange in the world, 
Thank you for all the answers received so far.
The exchanges for options trading that I have seen mentionned the most online (outside of this thread) are Deribit, Delta, Binance, FTX and LedgerX. Apparently, options trading on Bitcoin can even be done on the CME (traditional exchange).
I agree with everyone here that Binance is maybe the most safe crytpo CEX to deposit funds on for trading. I trusted also FTX since it is now the 2nd crypto exchanges by volumes and they have top notch security as Binance.
I don't know the other ones very much and how much they can compare outside of the safety of the deposit. I would appreciate any additional insights on that.