For the following questions, select the best of the answer choices given.
　 To prevent some conflicts of interest, Congress could prohibit high-level government officials from accepting positions as lobbyists for three years after such officials leave government service. One such official concluded, however, that such a prohibition would be unfortunate because it would prevent high-level government officials from earning a livelihood for three years.
　 The official’s conclusion logically depends on which of the following assumptions?

A、
Laws should not restrict the behavior of former government officials.
B、
Lobbyists are typically people who have previously been high-level government officials.
C、
Low-level government officials do not often become lobbyists when they leave government service.
D、
High-level government officials who leave government service are capable of earning a livelihood only as lobbyists.
E、
High-level government officials who leave government service are currently permitted to act as lobbyists for only three years.

【正确答案】 D

【答案解析】

文段中由禁止政府高层官员在离开政府部门后三年内接受院外游说集团提供的职位，得到结论：它将阻止高层政府官员在这三年里谋求生计，可以推断其中暗示政府高层官员离开政府部门后只能靠做院外游说集团成员来谋生，故本题选D项。