Your request was for which one of the five holds the most promise. You surely like to make it difficult. All are important, as well as some of the other comments.
My choice would be #2 Drive mission fit. People have the human need to feel needed and important. If you let them know what they do is important to the whole picture they will give you their best. But none of these stand alone. You can't communicate a mission without confident communications, without a great story, and it won't have any intrinsic value. Without all five of these it is just like a puzzle piece, colorful but with no meaning.