The arthropod, which is known as living fossil is

Options

A. Bombyx (silkworm)
B. Locusta (locust)
C. Limulus (king crab)
D. Apis (honeybee)

Answer

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks for the name of an arthropod that is known as a "living fossil."

2. **Understand the Term "Living Fossil"**: A living fossil refers to a species that has remained relatively unchanged over a long period of geological time and closely resembles its fossil ancestors.

3. **Consider the Options Provided**: The options given are Bumbax, silkworm, lostata, limulus, and honey bee.

4. **Analyze the Options**:
- **Bumbax**: Not commonly recognized as an arthropod or living fossil.
- **Silkworm**: While it is an important insect, it is not considered a living fossil.
- **Lostata**: This does not appear to be a recognized arthropod.
- **Limulus**: Known as the horseshoe crab, it is often referred to as a living fossil due to its ancient lineage and resemblance to fossils dating back over 450 million years.
- **Honey Bee**: Important for ecology and agriculture but not a living fossil.

5. **Conclude the Answer**: Based on the analysis, the arthropod known as a living fossil is **Limulus** (horseshoe crab).

**Final Answer**: Limulus

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