Final answer:
The study found no relationship between image valence and drug effectiveness, indicating that emotional states induced by unrelated images did not impact the perception of the anti-influenza drug.
Step-by-step explanation:
In the given study, researchers had participants view a fictitious anti-influenza drug paired with images that elicited positive, neutral, or negative feelings. The purpose was to determine the impact of image valence on the drug's effectiveness. The results of the study revealed no relationship between image valence and drug effectiveness (option b). It means that the emotional state evoked by the images did not influence the participants' perception of the drug.
The study design also considered the placebo effect by including a control group that received a sugar pill. This helped differentiate between the actual drug's effects and participant expectations or experimenter bias. Any differences in mood between the control and experimental groups could be attributed to the drug itself instead of placebo effect (option d).
Overall, the study did not find a correlation between image valence and drug effectiveness, suggesting that emotional states induced by unrelated images did not impact the perception of the anti-influenza drug.