【单选题】

Of the following 1980 median-income ratios，the greatest was the ratio of the median incomes of

A、graduates in Region Y to graduates in Region X

B、nongraduates in Region Y to nongraduates in Region X

C、graduates in Region Y to nongraduates in Region Y

D、graduates in Region X to nongraduates in Region X

E、graduates in Region X to nongraduates in Region Y