A. Most of the patients observed in the home environments were living with family members.
This is just a description of the home setup — it doesn’t tell us whether family presence increases or decreases depression, so it doesn’t really help test the conclusion.
B. There were some patients in the health care facility who would have preferred to remain in their home environments.
Patient preference might affect happiness, but it doesn’t directly show whether the stress-free environment is or isn’t the main reason for facility success.
C. The doctors observing patients in their home environments were more accredited than the doctors observing the other group.
Doctor accreditation affects observation quality, but the conclusion is about causes of depression bouts, not about measurement accuracy.
D. The dosage of anti-depressive medicine was the same for patients in both the groups studied.
This controls for one possible difference i.e medicine dosage but doesn’t address the most likely confound here — the stress or adjustment period from relocation.
E. The time period of study was sufficient for patients to acclimatize to new surroundings that could otherwise have caused severe anxiety.
If the time period wasn’t enough, higher depression bouts in home patients could just be due to temporary relocation stress, not because the home environment is actually worse. Knowing they had time to acclimate removes that doubt, so the conclusion becomes stronger.
ANSWER - E