A and C. Or, roam with a non mainland SIM so you can forego C. I can actually get by pretty well without C btw (I've yet to find a VPN that works with my phone OS), but it is nice to be able to use Google instead of Bing or baidu.

ETA: I should also point out that VPNs don't protect people from themselves (i.e. avoid taboo topics on social media, including WeChat).