这道题D选项看上去不错啊。题目说Comparisons of the average standards of living of the citizens of two countries should reflect the citizens’ comparative access to goods and services. 说明the citizens’ comparative access to goods and services只是Comparisons of the average standards of living of the citizens of two countries 的必要条件，所以D选项的comparative access to goods and services is only one of several factors relevant in determining quality of life可以构成But it is difficult to get an accurate comparison of average standards of living from these figures, 这样一个结论的基础。请nn指教。谢谢。
14. Which of the following, if true, best completes the argument below?
Comparisons of the average standards of living of the citizens of two countries should reflect the citizens’ comparative access to goods and services. Reliable figures in a country’s own currency for the average income of its citizens are easily obtained. But it is difficult to get an accurate comparison of average standards of living from these figures, because______
(A) there are usually no figures comparing how much of two different currencies must be spent in order to purchase a given quantity of goods and services
(B) wage levels for the same job vary greatly from country to country, depending on cultural as well as on purely economic factors
(C) these figures must be calculated by dividing the gross national product of a country by the size of its population
(D) comparative access to goods and services is only one of several factors relevant in determining quality of life（A）
(E) the wealth, and hence the standard of living, of a country’s citizens is very closely related to their income | 
