The convection current which arises when equatorial and polar regions of the earth receive unequal solar heat is called as:

Options

A. Land breeze
B. Sea breeze
C. Trade wind
D. Tornado

Explanation

To solve the question, we need to identify the convection current that arises due to the unequal heating of the Earth's surface, specifically between the equatorial and polar regions.

### Step-by-Step Solution:

1. **Understanding the Concept of Convection Currents**:
- Convection currents are movements of fluid (air or water) caused by differences in temperature and density. Warm air rises, and cooler air sinks, creating a circulation pattern.

2. **Identifying the Regions**:
- The equatorial regions receive more direct sunlight and are generally warmer, while the polar regions receive less sunlight and are cooler. This temperature difference leads to the formation of convection currents.

3. **Analyzing the Options**:
- **Land Bridge**: This term typically refers to a land connection between two larger landmasses and does not relate to convection currents.
- **Sea Bridge**: Similar to the land bridge, this term does not pertain to convection currents.
- **Trade Winds**: These are the prevailing winds that blow from east to west in the tropics, created by the convection currents resulting from the temperature difference between the equator and the poles.
- **Tornado**: This is a localized and violent windstorm, not directly related to the global convection currents caused by solar heating.

4. **Conclusion**:
- The convection current that arises when the equatorial and polar regions receive unequal solar heat is known as the **trade winds**.

### Final Answer:
The convection current which arises when equatorial and polar regions of the earth receive unequal solar heat is called the **trade wind**.

---