Which control is required of every AJAX page to manage the JavaScript files sent to the client and the communication between client and server?

Which control is required of every AJAX page to manage the JavaScript

1.	Which control is required of every AJAX page to manage the JavaScript files sent to the client and the communication between client and server?
A.	UpdatePanel
B.	ScriptManager
C.	AsyncPostBackTrigger
D.	None of the above.
Answer» C. AsyncPostBackTrigger