If you are given these options for dinner:

* Pie
* Cake
* Muffin
* Ice Cream

And you can have any of these options as you like and you can't have more than one of the same item. Then what are all the possible combinations?

For example you can have:

```
Pie
Pie, Cake
Pie, Cake, Muffin
Pie, Cake, Muffin, Ice Cream
Pie, Ice Cream
Cake, Muffin

etc...

```

Is there a way to find all possible combinations?