Rarely and hardly have negative connotations so it's "does he". If you use "doesn't he" you will create a double negative. - He hardly visits you does he (correct). - He hardly visits you doesn't he (incorrect). When you unfold it this means: He doesn't visit you often does he not (this is basically gibberish). Meaning he does visit often. Rarely and hardly are pretty much synonymous in this situation. They both mean infrequently.

I would use (b) in both cases because otherwise you are in danger of using a double negative. There is some flexibility here, in intonation too but : “Hardly” “Rarely” Are essentially negative in meaning. I hope that helps.

Does he)

b one is correct answer

Doesn't he?