Here is my situation. I am looking for a post-doc position. I have two choices, A and B.
My first choice is A. And I already got an un-official offer from A. I was told that A is working on a official offer. But I haven't got the official offer yet.
Now, my second choice, B, also send me an email. B tells me that he would like to give me an offer if I am interested in joining his lab. How should I reply? Is it appropriate to tell him that I am interested?