紧急求助～GWDTN24-18不懂！

Parland’s alligator population has been declining in recent years, primarily because of hunting.  Alligators prey heavily on a species of freshwater fish that is highly valued as food by Parlanders, who had hoped that the decline in the alligator population would lead to an increase in the numbers of these fish available for human consumption.  Yet the population of this fish species has also declined, even though the annual number caught for human consumption has not increased.

Which of the following, if true, most helps to explain the decline in the population of the fish species?

A.    The decline in the alligator population has meant that fishers can work in some parts of lakes and rivers that were formerly too dangerous.

B.    Over the last few years, Parland’s commercial fishing enterprises have increased the number of fishing boats they use.

C.    Many Parlanders who hunt alligators do so because of the high market price of alligator skins, not because of the threat alligators pose to the fish population.

D.    During Parland’s dry season, holes dug by alligators remain filled with water long enough to provide a safe place for the eggs of this fish species to hatch.

E.     In several neighboring countries through which Parland’s rivers also flow, alligators are at risk of extinction as a result of extensive hunting.

我的理解 ：

鳄吃鱼-鳄因为被猎，数量下降了-Expect因为鳄少了，鱼该多-可是鱼没升反降

问为什么？

正确答案是D，完全不理解

D选项说的是，鳄挖的洞有水，这些水使鱼的蛋有机会FU化。

且不说这个有关没关，如果a safe place for the eggs of fish to hatch，分明就是可能使鱼的数量增加啊。

完全糊涂掉了，我的理解哪里错了呢？请各位牛牛帮忙！

A.C.E.都很同意排除吧。

D它说干旱时，alligators挖洞使水充足，这样子就可以使鱼蛋正常孵化。现在alligators的数量下降了，自然没有去挖洞存水了，这样鱼蛋也就无法孵化，从而鱼的数量也下降了。

这样子还是说得很通的

不过我觉得B也能解释啊

捕鱼船的数量增加，这样鱼的数量减少也能解释啊

是不是因为出现了无关词呢？还是什么

但是解释题里可以有无关词出现啊

LZ如果只是不知道D为什么对，那就给我解释下B为什么错吧~

楼上的各位

many many thanks!