[quote=@AzazelSlayer]
Question 
Do I have to use all three or can I choose one of them and write a Entry for that one ?
[/quote]

If you're referring to the four bonus categories (Beating the Heat, Mm' Spicy etc), you don't need to write for any of them! You can choose to write for one or all of them to try and win them, but you can also write a story that doesn't pertain to any of them, as long as it loosely references the main prompt.

I think.