Taxonomic Hierarchy:
Taxonomic hierarchy is a system used to classify organisms into various categories based on their characteristics and evolutionary relationships. It provides a hierarchical structure that helps in organizing and classifying living organisms.

Categories in Taxonomic Hierarchy:
The taxonomic hierarchy consists of several categories, which are arranged in a descending series. Each category represents a different level of classification, starting from the most general to the most specific. The categories in taxonomic hierarchy, from highest to lowest, are as follows:

1. Kingdom: The highest and most general category. It represents the largest group of organisms sharing similar characteristics.
2. Phylum: It represents a major taxonomic group of organisms within a kingdom. It is further divided into smaller categories.
3. Class: It represents a group of similar orders within a phylum. It is a more specific category than phylum.
4. Order: It represents a group of similar families within a class. It is more specific than the class category.
5. Family: It represents a group of similar genera within an order. It is a more specific category than the order.
6. Genus: It represents a group of similar species within a family. It is more specific than the family category.
7. Species: The lowest and most specific category. It represents a group of organisms that can interbreed and produce fertile offspring.

Arrangement of Categories:
In taxonomic hierarchy, the categories are arranged in a descending series. This means that each category is more specific and less inclusive than the one above it. The arrangement follows a top-down approach, where the highest and most general category (kingdom) is at the top, and the lowest and most specific category (species) is at the bottom.

Explanation of the Correct Answer:
The correct answer to the question is option 'D' - descending series. This is because the categories in taxonomic hierarchy are arranged in a descending order, with each category being more specific and less inclusive than the one above it. The arrangement starts from the highest and most general category (kingdom) and goes down to the lowest and most specific category (species).

The descending series arrangement is logical as it allows for a systematic classification of organisms based on their shared characteristics and evolutionary relationships. It helps in organizing the vast diversity of living organisms into manageable categories, making it easier to study and understand their relationships and characteristics.

Overall, the descending series arrangement of categories in taxonomic hierarchy provides a hierarchical structure that allows for a systematic and organized classification of living organisms.