The correct answer is: A. a-3, b-2, c-1, d-4
Cracking is a process used to break down large hydrocarbon molecules into smaller ones. It is used in the petroleum industry to produce gasoline, diesel fuel, and other products.
Smelting is a process used to extract metals from their ores. It is used in the copper industry to produce copper metal.
Hydrogenation is a process used to add hydrogen to organic compounds. It is used in the food industry to produce hydrogenated fats, which are used in many processed foods.
Vulcanization is a process used to improve the properties of rubber. It is used in the rubber industry to produce tires, rubber bands, and other products.
Here is a brief explanation of each option:
- Option A: a-3, b-2, c-1, d-4. This is the correct answer. Cracking is used in the petroleum industry, smelting is used in the copper industry, hydrogenation is used in the food industry, and vulcanization is used in the rubber industry.
- Option B: a-2, b-3, c-4, d-1. This is incorrect. Cracking is not used in the rubber industry.
- Option C: a-2, b-3, c-1, d-4. This is incorrect. Smelting is not used in the food industry.
- Option D: a-3, b-2, c-4, d-1. This is incorrect. Hydrogenation is not used in the rubber industry.