You are implementing an ASP.NET AJAX page. You add two UpdatePanel controls named pnlA and
pnlB. pnlA contains an UpdatePanel control named pnlAInner in its content template. You have the
following requirements. Update panels pnlA and pnlB must refresh their content only when controls

that they contain cause a postback. Update panel pnlAInner must refresh its content when controls
in either pnlA or pnlB or pnlAInner cause a postback. You need to configure the panels to meet the
requirements. What should you do?

A.
Set the UpdateMode of pnlA and pnlB to Conditional. Set the UpdateMode of pnlAInner to
Always.

B.
Set the UpdateMode of pnlA and pnlB to Conditional. Set the UpdateMode of pnlAInner to
Conditional, and add AsyncPostBackTrigger elements to its Triggers element for every control in
pnlA.

C.
Set the UpdateMode of pnlA and pnlB to Always. Set the UpdateMode of pnlAInner to
Conditional.

D.
Set the UpdateMode of pnlA and pnlB to Always. Set the UpdateMode of pnlAInner to Always,
and add AsyncPostBackTrigger elements to its Triggers element for every control in pnlB.