Option 4: use your own SIM card
If you live in the EU, calls and internet usage on your cell phone cost the same whether you're in your own country or elsewhere in the EU. So you may not need to buy anything if rates, data speed and data amounts are just fine for your holidays as well. Do note that Switzerland is not a member state of the EU. Many providers do count Switzerland as a EU country. Some don't, so you'll pay more.
Try to estimate how much you will call and how much data you will need during your stay. Check the rates of your provider for calls and data in Switzerland. It can still be cheaper to buy a SIM card or Wifi hotspot. For fast internet, and especially if you travel with multiple people, renting a mobile Swiss Wifi hotspot is an excellent option.