Greetings and Birthday Quiz

The correct phrase is 'happy birthday', where 'birthday' is the word that completes it.

The correct answer 'hi.' is a common informal greeting, while the incorrect answers do not match the informal nature of the question.

The correct answer is 'Hello.' as it is the most commonly used greeting in English.

The correct answer is 'hi.' as it is a common informal greeting used in everyday conversations.

The correct answer is 'hi.' which is a common informal greeting. The incorrect answers 'bye.', 'hello.', and 'hey.' are also greetings but are not the correct response to the question posed.