__________ is considered as the highest category.

Explanation

**Step-by-Step Solution:**

1. **Understanding Taxonomic Hierarchy**: Taxonomy is the science of classification of living organisms. It organizes biological diversity into hierarchical categories.

2. **Identifying the Highest Category**: In the taxonomic hierarchy, the categories are arranged from the most general to the most specific. The main categories include:
- Kingdom
- Phylum
- Class
...