A clinical study tested a new pain medication and recorded average pain reduction (on a 10-point scale) at four dosages: 5 mg, -1.5; 10 mg, -3.8; 20 mg, -5.4; 40 mg, -5.5. The researchers concluded that increasing the dose beyond 20 mg yields no additional pain relief. The data most uniquely supporting the "no benefit beyond 20 mg" claim is ______
Which choice most logically completes the text using the data above?
- A
the 5 mg result of -1.5.
- B
the overall trend from 5 mg to 40 mg.
- Ccheck_circle
the near-identical reductions at 20 mg (-5.4) and 40 mg (-5.5), despite the doubling of dose.
- D
the 10 mg result of -3.8.
Explanation
"No benefit beyond 20 mg" requires showing that doubling from 20 to 40 mg produces almost no further effect. Choice C captures the flat 20→40 mg comparison (-5.4 vs. -5.5), uniquely supporting the plateau claim.