Analogy — Music : Notes\nSelect the pair that preserves “discipline/content unit” relation.

Introduction / Context:
“Music : Notes” links a field to its fundamental symbolic units. We need a similar mapping where the right term denotes basic elements used within the left field.

Given Data / Assumptions:

• Notes are the atomic symbols composing music (notation, melody).
• Numbers are the atomic symbols composing mathematics (quantities, operations).

Concept / Approach:
Reject pairs that mix medium with art (dance : music), institution with members (nations : UN), or tool with purpose (language : communication). Choose a field → units relation.

Step-by-Step Solution:

Verification / Alternative check:
Textbooks frame music in notes and mathematics in numbers; the analogy pattern is standard.

Why Other Options Are Wrong:

• Dance : Music — accompaniment, not elemental unit.
• Language : Communication — purpose, not building blocks.
• Nations : UN — organization membership, not content units.

Common Pitfalls:
Confusing function or accompaniment with elemental composition.

Final Answer:
Mathematics : Numbers