Which of the following is a creational design pattern?

Which pattern ensures a class has only one instance and provides a global point of access to it?

Which design pattern is used to represent the dependency between objects to notify other objects when there is a state change?

In which design pattern do objects take on multiple responsibilities instead of specializing in one?

Which design pattern provides an interface for creating families of related or dependent objects without specifying their concrete classes?

Which structural design pattern allows objects with incompatible interfaces to work together?

Which behavioral design pattern allows an object to alter its behavior when its internal state changes?

Which pattern is often used to provide a simplified interface to a complex subsystem?

Which design pattern encapsulates a request as an object, thereby allowing users to parameterize clients with queues, requests, and operations?

Which design pattern is used when you want to create a family of related objects that are intended to be used together?

Which design pattern allows an object to change its behavior when its state changes, often by having a state class for each possible state?

Which creational design pattern allows you to create different representations of a complex object?

Which structural design pattern composes objects into tree structures to represent part-whole hierarchies?

Which design pattern involves the creation of an object that holds the state of another object and allows restoring it later?