Which option is correct - intonation on the question tag goes up/down?
Which option(s) is/are correct -
1)intonation on the tag goes up - a responder waits for YES
2)tag intonation goes down - a responder waits for NO
3)tag intonation goes up to find out an interviewer's opinion
4)tag intonation goes down - to get their agreement with a responder?

Question

Which option is correct - intonation on the question tag goes up/down?
Which option(s) is/are correct - 
1)intonation on the tag goes up - a responder waits for YES 
2)tag intonation goes down - a responder waits for NO  
3)tag intonation goes up to find out an interviewer's opinion  
4)tag intonation goes down - to get their agreement with a responder?

Answer

Interesting question - Are you studying linguistics?

How does intonation affect the meaning of a question tag?
A question tag said with falling intonation ↘ means ‘I know what I am saying is correct’.
A question tag said with rising intonation ↗ means ‘I’m not sure if this is true, please answer’.
Source:
https://thesoundofenglish.org/question-tag-intonation/

Also, there are youtube videos on the topic.
(brief clear)
https://www.youtube.com/watch?v=D8MljmNNsDs

(longer)
https://www.youtube.com/watch?v=k1Qh4ylT6M8
https://www.youtube.com/watch?v=Hng7-Rvnu40