A. Set the Page attribute to AutoEventWireup="False". Remove the attribute onunload="Page_Unload" from the Web Form element.
B. Set the Page attribute to AutoEventWireup="False". Add the attribute OnUnload="Page_Unload" to the Web Form element.
C. Set the Page attribute to AutoEventWireup="False". Add the Web Form attribute autocomplete=on.
D. Set the Page attribute to AutoEventWireup="True".