[请教]OG-86

whoody

题目：
86.Hardin argued that grazing land held in common (that is, open to any user) would always be used less carefully than private grazing land. Each rancher would be tempted to overuse common land because the benefits would accrue to the individual, while the costs of reduced land quality that results from overuse would be spread among all users. But a study comparing 217 million acres of common grazing land with 433 million acres of private grazing land showed that the common land was in better condition.

答案：

(D) If one user of common land overuses it even slightly, the other users are likely to do so even more, with the consequence that the costs to each user outweigh the benefits.

解释：

The study indicates that common lands are in better shape than private lands. The best answer, D, indicates that, contrary to Hardin’s claim, it is in each rancher’s self-interest not to overuse common land, which would explain why common lands are in relatively good shape.

我咋看不出来答案哪里说了rancher's self-interest not to overuse common land呢？请指教。