WPF provides the ability to create ____________ -- actions or tasks that may be triggered by many different user interactions.

Which of these remarks about formal parameters is correct?

a. A formal parameter is a kind of place holder that is filled with the argument at the time of call to the function. b. A call-by-value formal parameter is a global variable that is initialized to the value set just before the function is called. c. A call-by-reference formal parameter is modeled on a substitution mechanism. The argument should be an expression, not a variable, since there is never a need to assign such a variable. d. The & (ampersand) character is used to indicate call-by-reference. This is done by placing the & after the type name which is followed by the parameter name in the definition of the parameter in the function header. e. The argument corresponding to a call-by-value parameter cannot be changed by anything that happens in the function call.

You represent a decision in a flowchart by drawing a decision symbol, which is shaped like a ____.

A. parallelogram B. square C. diamond D. circle