Intermediate category is

Options

A. (a) category in addition to obligate categories
B. (b) subphylum
C. (c) subspecies
D. (d) of the above.

Answer

**Step-by-Step Solution:**

1. **Understanding the Concept of Categories:**
- Categories in biological classification refer to the ranks used to organize living organisms. These ranks help in understanding the relationships and hierarchies among different organisms.

2. **Types of Categories:**
- There are two main types of categories:
- **Major Categories:** These include Kingdom, Phylum, and Class. They represent higher levels in the taxonomic hierarchy.
- **Minor Categories:** These include Order, Family, Genus, and Species, which are lower ranks in the hierarchy.

3. **Traditional vs. Intermediate Categories:**
- The traditional categorization system (also known as obligate categories) was established when the estimated number of species was around 1.7 million.
- With the discovery of new species and the extinction of others, the current estimate of species on Earth has risen to about 8.7 million. This increase has led to the identification of species that do not fit neatly into the traditional categories.

4. **Definition of Intermediate Categories:**
- Intermediate categories are additional ranks that help classify organisms that do not fit into the established major or minor categories.
- Examples of intermediate categories include subkingdom, subphylum, and subclass. These categories provide a more nuanced classification for certain organisms.

5. **Evaluating the Options:**
- The question provides several options regarding what the intermediate category is:
- A) Category in addition to obligate categories.
- B) Subphylum.
- C) Subspecies.
- D) All of the above.
- Since all the options (A, B, C) correctly describe aspects of intermediate categories, option D ("All of the above") is the correct answer.

**Final Answer:**
The intermediate category is defined as a category in addition to obligate categories, which includes subphylum and subspecies. Therefore, the correct answer is D) All of the above.

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