Archaeologist: The mosaics that were removed from Zeugma, the ancient city now flooded by the runoff from Turkey’s Birecik Dam, should have been left there. We had all the information about them that we needed to draw archaeological conclusions, and future archaeologists studying the site, who may not have access to our records, might be misled by their absence.

Which one of the following, if assumed, most helps to justify the reasoning in the archaeologist’s argument?

Traffic engineers have increased the capacity of the Krakkenbak Bridge to handle rush-hour traffic flow. The resultant increase in rush-hour traffic flow would not have occurred had the city not invested in computer modeling technology last year at the request of the city’s mayor, and the city’s financial predicament would not have been resolved if the traffic flow across the bridge during rush hour had not been increased.
Which one of the following can be properly inferred from the information above?

Court analyst: Courts should not allow the use of DNA tests in criminal cases. There exists considerable controversy among scientific experts about how reliable these tests are. Unless there is widespread agreement in the scientific community about how reliable a certain test is, it is unreasonable for the courts to allow evidence based on that test.

The court analyst’s reasoning is flawed because it fails to take into account that

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If all of the statements above are true, which one of the following must be true?

Microbiologist: Because heavy metals are normally concentrated in sewage sludge during the sewage treatment process, the bacteria that survive in the sludge have evolved the unusual ability to resist heavy-metal poisoning. The same bacteria also show a strong resistance to antibiotics. This suggests that the bacteria’s exposure to the heavy metals in the sewage sludge has somehow promoted their resistance to antibiotics.

Which one of the following, if true, most strengthens the microbiologist’s argument?