School rule implication (corrected): Premise (standardized): "The principal is in the school when the teachers are in the class." (Teachers in class ⇒ Principal in school) Select the pair that correctly reflects this implication.

Introduction / Context:
The original stem had grammatical issues; applying the Recovery-First Policy, we clarify the intended rule: whenever teachers are in class, the principal is in school. That is a straightforward implication.

Given Data / Assumptions:

• Premise: Teachers-in-class ⇒ Principal-in-school.
• Statements: (i) Principal in school; (ii) Principal in town; (iii) Teachers in class; (iv) Teachers in playground.

Concept / Approach:
We must select a pair that presents the antecedent and its guaranteed consequent, not the converse.

Step-by-Step Solution:

Verification / Alternative check:
Converse (i) ⇒ (iii) is not guaranteed. The principal might be in school for other reasons, so (i)(iii) does not necessarily hold.

Why Other Options Are Wrong:

• (b) asserts the converse, not entailed.
• (c) and (d) introduce unrelated or contradictory locations.
• None of these is wrong because a correct pair exists.

Common Pitfalls:
Reversing the implication; thinking "principal in school" forces "teachers in class."

Final Answer:
(iii) and (i)