“e” is the correct answer, according to them. So any two people, of any makeup and kind, can be a family, as long as they care for and take care of each other. Heck, they might not even live together.
Like I said the answer was poorly written, but essentially correct. Not all people in a family are related by blood. Not all families have two parents. Not all have two working adults. If we reduce this to selecting the most correct answer rather than the strictly correct answer then "e" is still it