Hydrological pathway — arrange water bodies/processes logically 1. Rivulet 2. Ocean 3. Tributory 4. River 5. Sea 6. Rain

Introduction / Context:
This item captures a simplified surface-water pathway from precipitation to large water bodies. Correct reasoning uses small-to-large flow, reflecting how minor streams combine to form major bodies that ultimately drain to seas and oceans.

Given Data / Assumptions:

• Rain initiates flow.
• Rivulets are tiny streams.
• Tributories feed larger rivers.
• Rivers flow to the sea; seas connect to the ocean.

Concept / Approach:
Build from the origin (precipitation) toward successively larger aggregations of water flow and storage.

Step-by-Step Solution:
6 (Rain) → 1 (Rivulet) → 3 (Tributory) → 4 (River) → 5 (Sea) → 2 (Ocean).

Verification / Alternative check:
Geographical flow networks commonly depict this hierarchy.

Why Other Options Are Wrong:

• They place seas/oceans before the formation of rivers/tributaries or invert the natural flow.

Common Pitfalls:
Confusing tributory vs rivulet magnitude; here tributories feed rivers and are larger than tiny headwater rivulets.

Final Answer:
6 1 3 4 5 2