What happens next in this paragraph?

How to manually update google play 
Head to security settings. 
Tap the gear icon on your home screen or apps drawer then find " security " from the options. 
Check " unknown sources.
Available choices:
[A]. Scroll down through the security settings until you get to " unknown sources " and make sure it has a check mark beside it. This will allow you to install apps that aren't from the version of google play you are currently running (like the updated version)..
[B]. " this is a search item from google play's settings menu on the bottom portion of the main page. A list of all the sources you may have online can now be searched..
[C]. Scroll down the list of possible sources. Tap " disabling sources " in the list to disable the source..
[D]. " tap on the " unknown sources " button to confirm your app won't hide you under your profile page and/or firewall. If your app is password protected, you can skip this step..
[A].