Which of the following most logically completes the passage?
Concerned about the financial well-being of its elderly citizens, the government of Runagia decided two years ago to increase by 20 percent the government-provided pension paid to all Runagians over 65. Inflation in the intervening period has been negligible, and the increase has been duly received by all eligible Runagians. Nevertheless, many of them are no better off financially than they were before the increase, in large part because __________.
"only by enough to provide them with a comfortable living"
That means if elderly parents' comfortable living conditions are below the comfortable line just to 200$,their children will supplement the income of 200$,meanwhile goverment increase the pension to 20%,thus the same parents' comfortable living condition require only 180$ to the the comfortable line,their children will supplement the income of 180$,not 200$.