What do you mean by “make a decision”? It should return a value and the value will be an array. Your function is not returning anything at the moment. You are using console.log to display something to the console, but that is not the same as returning a value.
You should have already learned about the slice method which allows you to return “part” of an existing array. If you could take the “parts” of a a certain size and “push” them into a new array, that is an approach you could take. If you do not remember the slice method, see below for the challenge where it was introduced.