My pre-med committee is writing my med school letter and requires all LORs be in before they start to write the letter. I have asked for 5 letters, and 4 have now reached the school. Of the 4 letters, three are from science professors and one is from a clinic volunteer supervisor. The fifth letter is to be from my undergraduate advisor. I never took a class from him or did research under him, but I did visit him regularly over three years to discuss class schedules, future plans, summer plans, etc. I asked for the letter about two months ago and asked if he could send it in by July 1. He said it was no problem. When I checked with my pre-med committee on July 15, however, they hadn't received anything. I asked my advisor and he said that he hadn't finished it yet, but that he'll work on it. What do you think I should do? a) wait for his letter? b) tank the letter and give the committee the go-ahead? c) something else?