Analogy — Abstraction and medium/container: Medicine : Pills

Introduction / Context:
“Medicine : Pills” maps a substance/discipline to a common unit/medium of delivery. We need a similar abstraction→physical medium mapping.

Given Data / Assumptions:

• Medicine is commonly delivered in the unit form of pills.
• Knowledge is commonly stored/conveyed in books.

Concept / Approach:
Prefer a pair where the second item is a standard physical carrier of the first.

Step-by-Step Solution:

Why Other Options Are Wrong:

• Spices : Food: food is not a container for spices; spices are ingredients in food (inverse relation).
• Watch : Time: a watch measures time; time is not carried by a watch.
• Radio : Sound: radio transmits sound; not a storage medium like pill/book.
• None of these: incorrect because “Knowledge : Books” fits well.

Common Pitfalls:
Confusing function (measure/transmit) with medium (store/deliver).

Final Answer:
Knowledge : Books