I think the answer is D.
The first statement proposes this idea: High level government officials can't take up jobs as lobbyists for three years after leaving the service.
Counter argument: This would render them jobless.
So if you put these two statements together, what do you think the meaning conveyed is? The fact that prevention of these high level officials from taking up a lobbyist position for three years would render them jobless.
What is the underlying tone saying? That they don't have any other livelihood source.
Now look at the options:
A. This is not even directly related to the statement -
WrongB. This is partially true and can be confusing, but by saying lobbyists were previously high level officials, it's not really saying that all high level officials were only lobbyists. They might have had other opportunities. -
WrongC. Talking about low level officials doesn't prove anything to us since our argument is based on what these high level officials do or don't do once they leave the government -
WrongD. This is the most relevant answer. It says high level officials can only become lobbyists after leaving the service. The argument in question says the new rule will render these officials jobless. It matches up. -
Correct (But let's look at the last option just in case)
E. This doesn't make any logical sense either. If they're only permitted to act as lobbyists for three years, what's the point of bringing the new rule? In either case, this doesn't serve to be the assumption for the argument the official proposed. -
WrongHope this helps.