This is a past paper of a national test in Thailand. (Manee is a common Thai name and Songla is a province). The answer to this question is (4)How have you been? But I wonder why (3)How do you do? is wrong. I think I can just fill in any greeting so (3) and (4) are both correct.
So is (3)How do you do? okay for this question? and what is the difference between those two?
Best Answer
Because How to you do? is all but dead. But when it is/was used, you only use it for someone you have never met before. And thirdly the proper response to How do you do? is How do you do?
After the greeting Hi, the question How have you been? is natural and actually used.