If ifs and buts were candy and nuts, we’d all have a merry christmas.
If this were a four-way stop Vehicle A would have the right of way (<- is that supposed to be hyphenated?). I still think vehicle A technically has the right-of-way even though it makes more logical sense for Vehicle B to proceed first.
I went with B. as someone mentioned earlier, if there is an accident, police won’t care who was there first. B has less lanes of traffic to cross over or through.
In real life, I usually wave the person on or play rock, paper, scissors with them. Most people don’t get it though.