Why are most social scientists critical of the "official poverty thresholds?" .

A. Because the thresholds overestimate the number of people in poverty

B. Because the thresholds are based upon spending 1/3 of one's income on food and the number really should be 2/3 of one's income

C. Because the thresholds tend to underestimate the number of people in poverty

D. Because poverty is a social construction that doesn't have a basis in reality