Options are accessible by clicking the down arrow button on the first button as seen in the picture above.
Submits just the URL seen in the edit field
Opens a new dialog to index more than one URL at once
Change Number of Threads
The program can submit to more than one site at once. You can change the default number here from 10 to anything you like. Make sure you have the resources for it and not use too high numbers.
Enables the use of proxies for the submission. This is not required and can be left unchecked for most users.