How can I make my question "Optional" or "Compulsory"?

All questions are set to compulsory by default but if...

• You have a highly sensitive question, or
• For whatever reason you have a very difficult question to answer, or
• Just want respondents to be able to skip the question if they don't know the answer or don't want to answer,

...then you can untick the "Make Compulsory" tickbox to make your question optional.

The Image question type is the only question type that is not compulsory, i.e. optional by default.