Which of the following is richest in fossil?

Options

A. Basalt
B. Granite
C. Lava
D. Sedimentary rock

Answer

### Step-by-Step Solution:

1. **Understanding Fossils**:
- Fossils are the preserved remains or traces of organisms from the past. They can include bones, teeth, shells, and other hard parts of organisms that have undergone fossilization.

2. **Formation of Fossils**:
- Fossils typically form when organisms die and their remains are buried under layers of sediment. Over time, these layers can harden into rock, preserving the remains within.

3. **Types of Rocks**:
- There are three main types of rocks: igneous, metamorphic, and sedimentary. Each type has different characteristics and formation processes.

4. **Identifying the Richest Source of Fossils**:
- Among these rock types, sedimentary rocks are known to be the richest in fossils. This is because they are formed from the accumulation of sediments (like sand and silt) that settle in layers, often in environments such as oceans, lakes, and swamps.

5. **Conclusion**:
- Therefore, the answer to the question "Which of the following is richest in fossil?" is sedimentary rock.

### Final Answer:
- The richest source of fossils is **sedimentary rock**.

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