You are creating a Windows Workflow Foundation custom activity class named SmtpActivity by using Microsoft .NET Framework 3.5. You create an activity designer named SmtpActivityDesigner for the custom activity. You need to ensure that the Microsoft Visual Studio 2008 designer for Windows Workflow Foundation invokes the SmtpActivityDesigner designer each time the custom activity is placed in the workflow designer window. What should you do?
A.
Place the following attribute on the SmtpActivityDesigner class.
[ActivityDesignerTheme(typeof(SmtpActivity))]
B.
Place the following attribute on the SmtpActivity class.
[ActivityDesignerTheme(typeof(SmtpActivityDesigner))]
C.
Place the following attribute on the SmtpActivityDesigner class. [Designer(typeof(SmtpActivity))]
D.
Place the following attribute on the SmtpActivity class. [Designer(typeof(SmtpActivityDesigner))]