Communication : Message :: — Pick the pair that mirrors “process → content/vehicle” mapping.

Introduction / Context:
“Communication : Message” pairs an act/process with what it conveys (its content/vehicle). We must find an option where the first term is a process of conveying and the second term is the typical content/medium it uses.

Given Data / Assumptions:

• Communication conveys a message.
• Expression often uses words (or other symbols) as vehicles.

Concept / Approach:
“Expression : Words” parallels “communication : message” as process → vehicle/content. Other options either swap cause/effect or mix categories.

Step-by-Step Solution:
Preserve mapping: action/process → content/vehicle.Select “Expression : Words.”

Verification / Alternative check:
Common phrasing: “express yourself in words.”

Why Other Options Are Wrong:

• Humor : Delight — effect on audience, not conveyed content vehicle.
• Clarification : Doubt — opposite effect relation.
• Emission : Cosmic — category error.
• Instruction : Syllabus — plan vs. teaching; directionality off.

Common Pitfalls:
Choosing cause–effect rather than process–content mapping.

Final Answer:
Expression : Words