<span>D. the poverty threshold. This differs based on geography (certain areas of the country are more expensive to live in than others) and family size.</span>
In the United States, the poverty threshold (the minimum level of income possible around the country) is calculated every year considering the total cost a basic services and goods, like food, house, bills...
So, being below the poverty threshold means that basic need cannot be cover, which is an poor economical state, that's why option d is the answer.
