PSAT Reading Question 595: Answer and Explanation

Question: 595

Based on the information in the passage and on the figure, which of these antibiotics would be most helpful in treating someone with an E. coli infection, assuming the patient was not allergic to any antibiotics and had no other illnesses besides the E. coli infection?

• A. Vancomycin
• B. Ciprofloxacin
• C. Amoxicillin
• D. Staphylococcus

Correct Answer: B

Explanation:

(B) Lines 68–70 state that the "zone with the largest diameter typically signifies that it will be the best at fighting infection." Under the E. coli column (second column), ciprofloxacin has the largest diameter at 17 mm. It would therefore be the most effective antibiotic in this particular instance, as in choice (B). Vancomycin would be the most effective medication against S. aureus, not against E. coli. Amoxicillin is the second-most effective. Not only is there no data on Staphylococcus, but also it is actually a bacterial strain and not an antibiotic.