Statement: “Animals live on oxygen.” Conclusions: I. Plants do not live on oxygen. II. Anything that needs oxygen must be an animal.
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Aif Conclusion I follows
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Bif Conclusion II follows
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Cif either Conclusion I or II follows
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Dif neither Conclusion I nor II follows
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ENone of these
Answer
Correct Answer: if neither Conclusion I nor II follows
Explanation
Introduction / Context:The statement affirms a property of animals: they require oxygen. It does not make exclusivity claims about plants or all oxygen-using entities. We test the two conclusions for necessary implication.
Given Data / Assumptions:
- All animals need oxygen.
- Nothing is said about plants' respiration or about other oxygen-using organisms.
Concept / Approach:Conclusion I excludes plants from oxygen use; the premise is silent on plants. Conclusion II makes oxygen-use a sufficient test for being an animal; again, the premise does not reverse the implication.
Step-by-Step Solution:1) I: Not stated; plants may also use oxygen (e.g., for respiration), but the premise neither confirms nor denies it → does not follow.2) II: The premise is “animal ⇒ needs oxygen,” not “needs oxygen ⇒ animal.” Illicit conversion → does not follow.
Verification / Alternative check:Only if exclusivity or biconditionality were asserted would I/II follow. They are not.
Why Other Options Are Wrong:Any option admitting I or II imports unstated exclusivity.
Common Pitfalls:Reversing logical direction; assuming “only animals” need oxygen.
Final Answer:if neither Conclusion I nor II follows