What is the recommended method to ensure access of active Communities on a mobile device?

Universal Containers needs to roll out mobile access in their Community.

Their Community environment is as follows:

• Five active Communities

• Four of the active Communities are built on the Napili template; one is built in a Visualforce/Tab container

• Mobile device: Apple iPhone (i0S)

What is the recommended method to ensure access of active Communities on a mobile device?
A . Access four template -based Communities via Salesforce1 ‘OS app and Visualforce/Tab Community via mobile browser
B . Access all Communities via Salesforce1 iOS app
C . Access four template -based Communities via mobile browser and Visualforce/Tab community via Salesforce1 mobile browser app
D . Access all Communities via mobile browser using the Community URL