Which of the following most logically completes the passage? Concerned about financial well-being（n.幸福，舒适）of its elderly（a.较老的）citizens, the government of Runagia decided two years ago to increase by 20 percent the government-provided pension（U.退休金）paid to all Runagians over 65. Inflation in the intervening period has been negligible, and the increase has been duly(ad.适当，及时) received by all eligible Runagians. Nevertheless, many of them are no better off financially than they were before the increase, in large part because ________. A. They rely entirely on the government pension for their income B. Runagian banks are so inefficient that it can take up to three weeks to cash a pension check C. They buy goods whose prices tend to rise especially fast in times of inflation D. The pension was increased when the number of elderly Runagians below the poverty level reached an all-time high E. In Runagia children typically supplement the income of elderly parents, but only by enough to provide them with a comfortable living
答案是E. 如何解释？ C和D为什么不可以？想不明白． | 
ension增加20%,但是需要Pension的人数也同时达到了了一个相当高的数量,那么人均得到的Pension是否就没有得到相应的提高,所以many of them are no better off financially than they were before the increase.不知道我的理解是否有误?
