The software doesn't support the MP4 file format. By default, if you use the first 2 options in the application, you will have the possibility to choose as the export format the following types: IFO, VOB and BUP. There is no MP4. For that you will need another converter, and luckily, there are many available on the Internet.
Use the results from the following list to find an application that converts the DVDs to the MP4 format: http://software.informer.com/search/dvd+to+mp4