The no. of categories listed in Red Data Book by IUCN is

Options

A. 3
B. 4
C. 9
D. 8

Answer

**Step-by-Step Solution:**

1. **Understanding the Red Data Book**: The Red Data Book is a document that lists rare and endangered species. It serves as a critical tool for conservation efforts by providing information on the status of various species.

2. **Role of IUCN**: The International Union for Conservation of Nature (IUCN) is responsible for compiling and maintaining the Red Data Book. It aims to assess the conservation status of species and promote their protection.

3. **Categories in the Red Data Book**: The IUCN has classified species into several categories based on their risk of extinction. These categories help in understanding the conservation needs of different species.

4. **Listing the Categories**: The categories defined by IUCN in the Red Data Book are:
- Extinct
- Extinct in the Wild
- Critically Endangered
- Endangered
- Vulnerable
- Near Threatened
- Least Concern
- Data Deficient
- Not Evaluated

5. **Counting the Categories**: By counting the categories listed above, we find that there are a total of **9 categories** in the Red Data Book as defined by IUCN.

6. **Conclusion**: Therefore, the answer to the question is that the number of categories listed in the Red Data Book by IUCN is **9**.

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