TextThe American definition of success is largely one of acquiring wealth and a high material standard of living. It is not surprising, (1) , that Americans have valued education for its monetary value. The belief is widespread in the United States (2) the more schooling people have, the more money they will (3) when they leave school. The belief is strongest (4) the desirability of an undergraduate university degree, or a (5) degree such as medicine or law (6) the undergraduate degree. The money value of graduate degrees in (7) such as art, history, or philosophy is not (8) great.This belief in the monetary value of education is (9) by research outcomes on income. Ben Wattenberg, a social scientist, estimates that in the (10) of a lifetime a man (11) a college school diploma in 1972 could earn about $380,000 more than a man who (12) had a high school diploma. Perhaps this helps to explain survey (13) which showed that Americans who (14) they had lived their lives differently in some way regretted (15) of all that they did not get more education. The regret is (16) by those who have made (17) to the top and by those who have not. (18) a man like Douglas Fraser, the president of the United Auto Workers Union, a nationally known and successful leader, was (19) by regrets that he did not climb higher on the (20) ladder. 20（）

A. educational
B. political
C. commercial
D. social