In India, the overall Index of Industrial Production assigns a combined weight of 37.90 percent to the Eight Core Industries. Which of the following are among these Eight Core Industries: 1. Cement 2. Fertilisers 3. Natural gas 4. Refinery products 5. Textiles?

Introduction / Context:
The Eight Core Industries form a crucial part of the Index of Industrial Production in India and act as leading indicators for the performance of the industrial sector. Competitive exams frequently ask which sectors are included in this group and which are not. This question focuses on identifying which of the listed items are part of the Eight Core Industries and which one is excluded.

Given Data / Assumptions:

• The Eight Core Industries together have a weight of 37.90 percent in the Index of Industrial Production.
• We are given five items: cement, fertilisers, natural gas, refinery products, and textiles.
• The task is to pick the correct combination that includes only those industries that belong to the Eight Core Industries.
• We assume the standard official list of core industries used by the Government of India.

Concept / Approach:
The Eight Core Industries currently recognised in India are coal, crude oil, natural gas, refinery products, fertilisers, steel, cement, and electricity. These sectors are called core because they supply essential inputs to many other industries and are critical for infrastructure and energy. Among the items listed in the question, cement, fertilisers, natural gas, and refinery products are clearly in the official list. Textiles, however, are not part of the Eight Core Industries, even though textiles are important for exports and employment.

Step-by-Step Solution:
Step 1: Recall the Eight Core Industries: coal, crude oil, natural gas, refinery products, fertilisers, steel, cement, and electricity.Step 2: Check item 1, cement. This is in the list of core industries.Step 3: Check item 2, fertilisers. This is also in the list of core industries.Step 4: Check item 3, natural gas. Natural gas is recognised as one of the Eight Core Industries.Step 5: Check item 4, refinery products. Petroleum refinery products belong to the group of Eight Core Industries.Step 6: Check item 5, textiles. Textile industry is important but is not included in the official list of Eight Core Industries.Step 7: Therefore, items 1, 2, 3, and 4 are core industries, while item 5 is not. The correct option is the combination 1, 2, 3 and 4 only.

Verification / Alternative check:
Government publications and exam guides on Indian economy list the Eight Core Industries and provide their respective weights. These lists always include cement, fertilisers, natural gas, and refinery products, but they do not include textiles. Instead, textiles are captured under other manufacturing categories in the Index of Industrial Production. This direct comparison verifies that only the first four items in the question belong to the Eight Core Industries.

Why Other Options Are Wrong:
1 and 5 only: This leaves out fertilisers, natural gas, and refinery products, which are core industries, and wrongly includes textiles.

2, 3 and 4 only: This omits cement, which is a recognised core industry, so the combination is incomplete.

1, 2, 3, 4 and 5: This option incorrectly includes textiles along with the real core industries.

Common Pitfalls:
Students sometimes guess that all large industries, including textiles, must be core industries, which is not correct. Others may forget one or two items from the list of eight and mis select a partial combination. A useful memory aid is to remember that the Eight Core Industries are heavily skewed toward energy, basic materials, and infrastructure rather than consumer goods like textiles.

Final Answer:
The industries among the Eight Core Industries are cement, fertilisers, natural gas, and refinery products, that is, 1, 2, 3 and 4 only.