Fossils are studied by

Options

A. Tracing evolutionary history of organisms
B. Studying extinct organisms
C. Filling gaps in our study
D. Providing jobs to scientists

Answer

### Step-by-Step Solution

1. **Understanding Fossils**:
- Fossils are defined as the preserved remains or traces of ancient organisms. They can include entire organisms or just parts of them.

2. **Analyzing the Options**:
- The question provides four options regarding how fossils are studied. We need to evaluate each option to determine which one accurately describes the study of fossils.

3. **Evaluating Option 1 - Tracing Evolutionary History of Organisms**:
- This option suggests that fossils are used to trace the evolutionary history of organisms. This is indeed true because fossils provide valuable information about how different species are related and how they have evolved over time. This study is known as phylogeny.

4. **Evaluating Option 2 - Studying Extinct Organisms**:
- This option states that fossils are studied to understand extinct organisms. This is also correct since fossils are the remains of organisms that no longer exist, and studying them helps us learn about these extinct species.

5. **Evaluating Option 3 - Filling Gaps in Our Study**:
- This option implies that fossils are studied to fill gaps in our understanding. While fossils can provide information that helps fill gaps in knowledge, this option is vague and does not directly relate to the primary purpose of studying fossils.

6. **Evaluating Option 4 - Providing Jobs to Scientists**:
- This option suggests that studying fossils provides jobs to scientists. While it is true that paleontology is a field that employs scientists, this does not directly relate to the scientific study of fossils.

7. **Conclusion**:
- After evaluating all options, the most accurate answers are:
- **Studying Extinct Organisms** (Option 2)
- **Tracing Evolutionary History of Organisms** (Option 1)
- However, since the question asks for how fossils are studied, the best answer is **studying extinct organisms**.

### Final Answer:
Fossils are studied by **studying extinct organisms**.

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