Choose the sentence that shows the correct usage of commas. Because we had packed haphazardly we were unable to put all our supplies into the suitcases.

As you have not provided a sentence with commas, there is no comma error to correct.

What I can offer you is this:  your sentence rewritten to include a comma

Because we had packed haphazardly, we were unable to put all our supplies into the suitcases.

Explanation:

Whenever a dependent clause begins a sentence, that clause must ALWAYS be followed with a comma.