Cause–effect analogy: Fire : Smoke :: ?

Introduction / Context:
“Fire : Smoke” encodes cause → effect. We need a pair reflecting a similar natural causal relationship.

Given Data / Assumptions:
Seek a natural-process cause leading to a frequently observed effect, not mere association or location.

Concept / Approach:
“Cloud : Rain” mirrors a natural phenomenon: cloud formation often precedes rainfall under the right conditions. Other pairs are relational (child–school), locational (moon–sky), or tool/object (shoe–polish), not direct causation.

Step-by-Step Solution:

Why Other Options Are Wrong:
They do not encode the same immediate, natural causal direction.

Common Pitfalls:
Overextending associative relations as causal ones.

Final Answer:
Cloud : Rain