“Money” functions as the medium for a “Transaction.” Choose the pair with the same medium → communicative act relation.

Introduction / Context:
Medium–activity analogies pair the tool or medium with the process it enables. Money is the medium of exchange used in transactions. We must select an option where a comparable medium enables a corresponding communicative act.

Given Data / Assumptions:

• Money → Transaction (medium → economic act).
• We seek a parallel in communication.

Concept / Approach:
“Language : Conversation” mirrors the structure: language is the medium that makes conversation possible. “Ideas : Exchange” flips roles; ideas are what is exchanged, not the medium. “Water : Drink” is substance → action but not a standardized medium of an act in the same abstract sense; “Life : Death” is a contrast, not medium–activity.

Step-by-Step Solution:
1) Identify the abstract role “medium enabling act.”2) Map to communication: language enables conversation.3) Choose “Language : Conversation.”

Verification / Alternative check:
Economics frames money as a “medium of exchange”; linguistics frames language as the medium for verbal interaction (conversation).

Why Other Options Are Wrong:

• Ideas : Exchange: Ideas are exchanged; they are not the medium.
• Water : Drink: Physical consumption relation, not a general enabling medium.
• Life : Death: Antonymous states.

Common Pitfalls:
Confusing objects of exchange with the medium of exchange.

Final Answer:
Language : Conversation