阅读下列短文，从每题所给的四个选项（A、B、C或D）中，选出最佳选项
When you think of environmental problems you probably think of pollution, but the poaching (偷猎) of wild animals is one, too. Poaching has worried environmentalists for years and, despite laws, this terrible crime has yet to be stopped.
Poaching is a serious problem, especially in Africa and Asia. This crime is done for mercial profit (商业利益), meaning hunters kill animals illegally and sell their most worthy parts. Although poachers usually hunt tigers, elephants and rhinos, they kill sharks and whales, too. This illegal hunting has led to decreasing populations of many species.
Many nations have banned poaching, but enforcement (执行) is difficult. The small number of police officers trained to deal with this creates an unfair advantage for poachers.
Poachers usually kill animals for only one product: tigers are killed for their striped fur, elephants their ivory tusks and rhinos their large horn. The bodies of the animals are left to rot. Sharks' fins are cut off and their bodies thrown back into the ocean. Without fins they can't swim and will die. The illegally obtained fins are used to make shark fin soup.
The laws that “protect” animals are no more than pieces of paper. The current poaching bans need better enforcement, and I have a plan.
The number of enforcers needs to be increased so that there are enough to watch the herds and make sure poachers can't shoot the animals. The reserve parks in Africa should bee a huge zoo so that the animals can move but within a fenced area. Another idea is to build a concrete enclosure instead of fences. Watchtowers could be constructed so enforcers can monitor a wide variety of poacher targets. This may not completely end the problem, but it would slow it down.
Poaching is a serious problem and a criminal act. The effects of poaching will be felt for centuries to come, and if there are any still alive, the only place to see animals might be in a zoo.