Analogy — Hierarchy/aggregation mapping: A : Ocean :: Stone : B

Introduction / Context:
We seek parallel relationships of “member/smaller unit → larger set” in natural categories. A lake is a contained water body relative to the global oceanic system; a stone is a unit within the broader category of rock.

Given Data / Assumptions:

• Water-body hierarchy: lake (localized) vs ocean (global).
• Geologic hierarchy: stone (piece) vs rock (category/material).

Concept / Approach:
Preserve the part-to-whole or specific-to-general mapping across domains.

Why Other Options Are Wrong:

• River : Ocean — a process/flow relation; Pebble is a type/size of stone but does not mirror the first half cleanly across domains.
• Glacier : Granite — glacier is ice mass; granite is igneous rock; cross-domain and not parallel.
• Continent : Mountain — unrelated containment.

Final Answer:
A. Lake, B. Rock