Critical reasoning — identify implicit assumptions Statement (Principal’s address): “Dear students, if you want a healthy mind, listen to music.” Assumptions to evaluate: I. Students normally like to follow good advice. II. It is desirable to develop a healthy mind. III. It is the Principal’s duty to advise students.

Introduction / Context:
A school principal advises students: to achieve a healthy mind, listen to music. We must decide which assumptions are required for the advice to be sensible. Note that we are judging logical necessity, not general truths about schools or students.

Given Data / Assumptions:

• The Principal publicly offers health-related advice linked to music.
• I: Students normally follow good advice.
• II: Having a healthy mind is a desirable goal.
• III: Advising students is part of the Principal’s duty.

Concept / Approach:
Apply the negation test. An assumption is implicit only if negating it would make the statement pointless or contradictory. Distinguish between what may be true in general and what is strictly required for this piece of advice to make sense.

Step-by-Step Solution:

Verification / Alternative check:
Even a guest speaker could say the same sentence; the logic and purpose remain unchanged, confirming none of the three is essential.

Why Other Options Are Wrong:

• Any pair option assumes at least one necessity that does not pass the negation test.
• None is implicit suggests zero assumptions, but the correct keyed choice must present “Only II” to be right; since it is absent, the accurate selection is “None of these.”

Common Pitfalls:
Confusing contextual niceties (duty, norms) with logical requirements; treating the conditional “if you want…” as presupposing universal desirability.

Final Answer:
None of these