Which of the following is NOT one of the MOST common uses of Twitter?
Posting an idea of the moment.
Making a 4 contact.
Sharing a web link.
Organizing a political gathering.
It would be "Making a contact" that is not one of the most common uses of Twitter, since Twitter is used mostly to interact with people you already know, or who you "follow".
The thing for which Twitter isn't being used that often from the things which you've stated here would be organizing a political gathering. There are other channels which are much better suited for doing these things as are political gathering rallies.
