My answer to this question was removed by a moderator for no apparent reason. While brief, it provided the correct answer to the question. I'd like to know why it was removed. Could it be that there is a bias against shorter answers?
Short, low quality answers are automatically flagged by the system. From there they go into a review queue. If two reviewers (or one mod) agree then the post is deleted.
Here is an example which is halfway to being deleted as you can see from the comments and the timeline.