Which of the following is an example of a tertiary sector activity in the structure of an economy?

Introduction / Context:
In the study of Indian economy and development economics, activities are often grouped into three sectors: primary, secondary and tertiary. Primary activities involve extraction of natural resources, secondary activities involve processing and manufacturing, and tertiary activities involve services. Understanding which activities fall into each category is essential for interpreting sectoral contributions to GDP and employment. This question asks you to identify which activity represents the tertiary sector.

Given Data / Assumptions:
- Options include farming, manufacturing, dairying and trading.
- We need to pick the activity that belongs to the tertiary or service sector.
- We assume standard textbook definitions of the three sectors.

Concept / Approach:
Primary sector activities are concerned with the extraction or production of natural resources, such as farming, fishing, mining and dairying. Secondary sector activities transform these primary goods into manufactured products, such as in factories and workshops. Tertiary sector activities provide services that support production and consumption, such as trading, transport, banking, education and health care. Therefore, we simply classify each option by these definitions and select the one that clearly belongs to the service sector.

Step-by-Step Solution:
Step 1: Classify farming. Farming involves growing crops and is a classic primary sector activity based on agriculture. Step 2: Classify manufacturing. Manufacturing processes raw materials into finished or semi finished goods and is a typical secondary sector activity. Step 3: Classify dairying. Dairying involves production of milk and related products from animals, and is closely related to agriculture, so it belongs to the primary sector. Step 4: Classify trading. Trading involves buying and selling goods and providing distribution services. It does not produce physical goods but provides a service, so it belongs to the tertiary sector. Step 5: Therefore, trading is the correct example of a tertiary sector activity.

Verification / Alternative check:
A quick check is to remember that tertiary sector is also called the service sector. Activities like wholesale trade, retail trade, transport and financial services clearly fall into this category. Trading, by definition, refers to buying and selling goods and thus is a service that connects producers and consumers. None of the other options perform this type of service as their primary function, so trading is confirmed as the correct answer.

Why Other Options Are Wrong:
Farming is wrong because it is a primary sector agricultural activity based on direct use of land and natural resources.
Manufacturing is wrong because it forms part of the secondary or industrial sector, where physical transformation of inputs into finished goods takes place.
Dairying is wrong because it is associated with livestock and agriculture, and is treated as part of the primary sector along with other animal husbandry activities.

Common Pitfalls:
Students sometimes confuse secondary and tertiary activities when manufacturing firms also provide services like after sales support. However, the core manufacturing process is still secondary, while the service part is tertiary. Another confusion arises when people think of dairying as a processed product because milk is packaged, but the core dairying activity of producing milk is primary. Memorising a few typical examples for each sector, such as farming for primary, steel production for secondary and trading for tertiary, can help prevent such errors in competitive exams.

Final Answer:
The activity that belongs to the tertiary sector is trading.