the choose options are....

1.used to turn a request into a stand-alone object that contains all info about the reuqest

2.used to jnotify the state change of a prticular object to alist of dependant objects

3used to create an object without exxposing creation logic to client

4used to create single instance of object

5used to create an interchangable family of algorithims

Match the design pattern (on the left) with the appropriate description (on the right). Note: this question is worth 4 points total. Observer design pattern [ Choose ] v Command design pattern [ Choose ] Strategy design pattern [ Choose ] Singleton design pattern [ Choose ]