How to stop Whatsapp from sharing information with Facebook 

Instructions are here as to how to stop Whatsapp from sharing information with Facebook.

Facebook owns Whatsapp. I expect this simple opt out may not be so simple in the months and years to come. You may have to make a harder choice then when it comes to privacy on Whatsapp. In the meantime, you can follow those instructions to maintain the separation between your Whatsapp data and your Facebook data.