○　正解です。

If you answer 'everything' (全部) then you want all the food in house/country.
If you answer 'Something' (なにか) the answer is too unclear (曖昧).
'Anything' is usually used for questions and negative sentences (否定文).
For example :
Would you like anything to drink?
I don't want anything right now.
But this is a special case that means you will be happy whatever the other person cooks.