하나만 선택

• 1보기 1.

  NSObject → UIResponder → UIView → UIControl → UIButton

• 2보기 2.

  NSObject → UIView → UIResponder → UIControl → UIButton

• 3보기 3.

  NSObject → UIControl → UIResponder → UIView → UIButton

• 4보기 4.

  NSObject → UIResponder → UIControl → UIView → UIButton

• 5보기 5.

  UIResponder → NSObject → UIView → UIControl → UIButton