Insufficient data for conclusions

Steps:

• Question asks for conclusion from "the data," but no data provided.
• Choices involve correlations or causations between smoking and lung cancer.
• Without data showing rates, risks, or evidence, options cannot be evaluated.
• Not enough information to determine validity of any choice.

Why C is correct:

• Cannot confirm; lacks data tying smoking exclusively to lung cancer per causation laws.

Why the others are wrong:

• A: No data on likelihood or daily cigarette thresholds.
• B: No evidence smokers are immune or non-smokers fully protected.
• D: No data showing non-smokers inevitably get lung cancer.

Final answer: Not enough information.