(1) design pattern is used when you want to have only one instance of a given class. We often use (2)attributes to implement

What is the best term for number 1?

(1)design pattern

What's the best term for (1)?

singleton

facade

observer

delegation

-(1)--design pattern is used when you want to have only one instance of a given class. We often use--(2)-- attributes to implement__(1)_design pattern What's the best term for (1)? singleton facade observer delegation