Statement:\n“Animals live on oxygen.”\nConclusions:\nI. Plants do not live on oxygen.\nII. Anything that needs oxygen must be an animal.

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