Passage Summary: A doctor noticed a pattern where patients had rashes only on the side of their face used for phone calls and concluded the phones were the source of the irritation.

Conclusion: The facial rashes observed in the patients were caused by prolonged contact with their telephones.

Reasoning: The rashes appeared exclusively on the specific side of the face where each patient typically held their phone.

Analysis: This is a classic causal argument based on a correlation between phone use and rash location. To strengthen this, we want to see evidence that rules out other variables or shows the effect disappears when the cause is removed. Since this is an 'EXCEPT' question, the correct answer will be the one that either does nothing to help the doctor's case or actually undermines it. Keep an eye out for a choice that introduces a different potential cause or suggests the correlation is just a coincidence.