What is Backbone.sync used for?

A)  When Backbone wants to save or read a view to the server it calls out a function called as Backbone.sync.
B)  When Backbone wants to save or read a event to the server it calls out a function called as Backbone.sync.
C)  When Backbone wants to save or read a model to the server it calls out a function called as Backbone.sync.
D)  All of the above

Correct Answer :   When Backbone wants to save or read a model to the server it calls out a function called as Backbone.sync.