Answer:
A. The decision is irresponsible because choosing a vacation over a much needed new automobile is an improper use of scarce resources.
Explanation:
Think about it, the questions specifically states that a family decides to go on a vacation instead of buying a "much needed new automobile". The decision to go on a vacation is outright irresponsible, as a new car would be much more useful of their time and money, rather than a vacation. You can go on a vacation only around a season a year, however you can buy a car anytime as long as you have enough money.