You need to ensure that when the button is clicked,both update panels update the tim without generating a
postback.
What should you do?

A.
Add the following marktip to UpdatePanel1.
<Triggers>
<asp:PostBackTrigger ControlID=”btnSave” />
</Triggers>

B.
Set the UpdateMode property for the UpdatePanel2 to “Always”

C.
Add the following markup to UpdatePanel1
<Triggers>
<asp:AsyncPostBackTrigger ControlID=”btnSave”
EventName=”Click” />
</Triggers>

D.
Set the UpdateMode property for UpdatePanel2 to “Conditional”

Explanation:
I changed the answer. Choise (C)became different in the new exam(Panel1 rather than Panel2).
Shortly:The true answer is:
Add the following marktip to UpdatePanel1.
<Triggers>
<asp:PostBackTriggerControlID=”btnSave” />
</Triggers>