The brightest star in the sky:

Options

A. Sirius (Dog Star)
B. Canopus
C. Vega
D. Capella

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the brightest star in the sky. We need to identify which star holds this title.

2. **Identifying the Options**: The options provided are Fulmsa, Cassiopeia, Orion, Sirius, and none of these. We need to evaluate these options to find out which one is the brightest.

3. **Researching the Stars**:
- **Fulmsa**: Not widely recognized as a bright star.
- **Cassiopeia**: This is a constellation, not a single star.
- **Orion**: This is also a constellation, which includes several bright stars but does not refer to a single brightest star.
- **Sirius**: Known as the Dog Star, it is recognized as the brightest star in the Earth's night sky.

4. **Confirming Sirius as the Brightest Star**:
- Sirius is also referred to as Sirius A and is known for its brightness. The name "Sirius" means "Glowing Star" in Greek, which indicates its prominence in the night sky.
- Historically, Sirius has been well-known and observed since ancient times due to its brightness.

5. **Conclusion**: Based on the evaluation of the options, the correct answer is **Sirius**, which is the brightest star in the sky.

**Final Answer**: The brightest star in the sky is **Sirius**.

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