Business owner: Around noon in one section of the city, food trucks that sell lunch directly to customers on the sidewalk occupy many of the limited metered parking spaces available, thus worsening already bad traffic congestion.
Opposing Evidence
In one section of the city, food trucks occupy many of the limited metered parking spaces available, thus worsening already bad traffic congestion.
Evidence (since)
There is plenty of available parking and little traffic congestion in most areas of the city.
Conclusion
This bill [prohibiting food trucks from parking in metered spaces in any commercially zoned area] should be rejected.
Evaluate
"Thus" is usually a conclusion indicator, but it's not performing that function here. The second sentence in the argument describes a cause and effect relationship where the food trucks are causing traffic congestion.
It's important to recognize the recommendation in the final sentence—"this bill should be rejected." Recommendations like this almost always function as conclusions in LR arguments. And in this case, that recommendation acts more clearly as the conclusion of the argument than the statement about traffic congestion.
Food trucks parking in metered spots don't seem to be causing problems in most areas of the city. That seems like a decent reason to reject the proposed bill. But in LSAT LR, it's not enough for the link between the evidence and the conclusion to just be pretty good. We want to notice that the link between evidence and conclusion isn't airtight.
We could strengthen this argument by explicitly stating that, if problem caused by an activity does not affect most areas of the city, any bill which would prohibit that activity should be rejected.
Goal
Look for an answer which states a bill prohibiting an activity should be rejected if the activity does not cause problems in most areas. Beware of answers that bring in irrelevant details which don't actually impact the argument.