Complete combustion of most of the fuels produces ____ which is responsible for ____ .
(i) and (ii) are respectively

Options

A. oxygen and respiration
B. carbon and photosynthesis
C. carbon monoxide and pollution
D. carbon dioxide and global warming.

Explanation

To solve the question, we need to identify what is produced during the complete combustion of fuels and what effect that product has on the environment.

### Step-by-Step Solution:

1. **Understanding Complete Combustion**:
- Complete combustion occurs when a fuel burns in the presence of sufficient oxygen. This process typically produces specific products.

2. **Identifying the Products**:
- The primary products of complete combustion of hydrocarbons (common fuels) are carbon dioxide (CO2) and water vapor (H2O).

3. **Focusing on Carbon Dioxide**:
- Among the products, carbon dioxide is significant because it is a greenhouse gas.

4. **Understanding the Role of Carbon Dioxide**:
- Greenhouse gases, including carbon dioxide, trap heat in the Earth's atmosphere. This leads to an increase in the Earth's temperature.

5. **Connecting the Dots**:
- Therefore, we can conclude that the complete combustion of most fuels produces carbon dioxide, which is responsible for global warming.

### Final Answer:
The complete combustion of most of the fuels produces **carbon dioxide (CO2)** which is responsible for **global warming**.

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