题目选项分析

The retinas of premature babies are not fully developed at birth. Because their retinas are so delicate, premature babies sometimes lose their sight. Methods for preventing this syndrome, which is called retinopathy of prematurity, have improved, but the proportion of premature babies who lose their sight because of this syndrome has increased.

Which of the following, if true, best reconciles the apparent discrepancy described above?

【选项】Improved medical technology is saving the lives of premature babies who would previously have died, but these babies have even more delicate retinas than do other premature babies and are more apt to lose their sight.