Which protocol is responsible for addressing and routing packets to their destination?

Which of the following correctly initializes a doubly linked list in the default constructor?

A. head = nullptr; back = nullptr; B. head = 0; back = 0; count = 0; C. first = 0; last = 0; D. first = nullptr; last = nullptr; count = 0;

Which of the following best describes a hashtag?

A. Another term for meta data. B. An online encyclopedia. C. A word or phrase that creates an easily searched group of related messages. D. An online journal or diary.