961 - Logical Reasoning

Question : 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?

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