The outermost layer of our earth is called

Options

A. mantle
B. core
C. earth crust
D. benthos.

Explanation

**Step-by-Step Solution:**

1. **Understanding Earth's Layers**: The Earth is composed of three main layers: the core, mantle, and crust.

2. **Identifying the Outermost Layer**: Among these layers, the outermost layer is referred to as the "crust."

3. **Distinguishing Between Layers**:
- The **core** is the innermost layer of the Earth, which is further divided into the outer core and inner core.
- The **mantle** is the middle layer, located between the crust and the core.
- The **crust** is the layer we live on and is composed of various rocks and minerals.

4. **Thickness of the Crust**: The Earth's crust is approximately 20 to 25 miles thick.

5. **Conclusion**: Therefore, the correct answer to the question "The outermost layer of our earth is called" is the **Earth's crust**.

**Final Answer**: The outermost layer of our earth is called the Earth's crust.

---