It puzzles me that some of the choices for Clickable Math don't return a result. The image below shows four choices for clickable math. I would like
to know what the difference is between the four choices.

A:

The difference is that the first two choices are not clickable. The first one is a link to the MathJax documentation, and the second one is a link to the MathJax documentation.
The third choice is a link