You are writing code to handle events in your program. You define a delegate named Rectangle Handler like this: public delegate void Rectangle Handler(Rectangle rect); You also create a variable of the Rectangle Handler type as follows: Rectangle Handler handler; Later in the program, you need to add a method named Display-Area to the method invocation list of the handler variable. The signature of the Display-Area method matches the signature of the Rectangle Handler method. Any code that you write should not affect any existing event-handling code. Given this restriction, which of the following code should you write? a. handler = new Rectangle Handler(Display-Area).
b. handler = Display-Area.
c. handler += Display-Area.
d. handler −= Display-Area;.