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 the preserved remains or impressions of organisms from the past, typically found in the Earth's strata. They can include bones, shells, and even imprints of leaves.

2. **Purpose of Studying Fossils**: The study of fossils is crucial for understanding the history of life on Earth. It allows scientists to trace the evolutionary history of organisms, providing insights into how species have changed over time.

3. **Tracing Evolutionary History**: By examining fossils, scientists can reconstruct the lineage of organisms, identifying how different species are related and how they have evolved. This is essential for understanding the process of evolution.

4. **Studying Extinct Organisms**: Fossils provide valuable information about organisms that are no longer alive. By studying these remains, scientists can learn about the characteristics, behaviors, and environments of extinct species.

5. **Evaluating Options**:
- **Option A**: Tracing evolutionary history of an organism - This is correct.
- **Option B**: Studying the extinct organisms - This is also correct.
- **Option C**: Filling gaps in our study - This is not a primary purpose of studying fossils.
- **Option D**: Providing jobs to scientists - This is not relevant to the study of fossils.

6. **Conclusion**: The correct answers are A and B, as both options accurately reflect the purposes of studying fossils.