Species are considered as

Options

A. Real basic unit of classification
B. The lowest unit of biosystematies
C. Artificial concept of human mind which cannot be defined in absolute terms
D. Real units of classification devised by taxonomists

Answer

**Step-by-Step Solution:**

1. **Understanding Species**: A species is defined as a group of organisms that can interbreed and produce fertile offspring. This definition is crucial in understanding what constitutes a species.

2. **Taxonomic Rank**: Species is recognized as the basic unit of biological classification. It is the lowest rank in the taxonomic hierarchy, which organizes living organisms into categories.

3. **Classification in Biology**: In biological classification, species is considered the fundamental unit. It serves as the foundation for organizing and categorizing biodiversity.

4. **Evaluating Options**:
- The first option states that species are the "real basic unit of classification." This is correct.
- The second option refers to species as the "lowest unit of biosystematics." This is incorrect because species is a unit of taxonomy, not biosystematics.
- The third option describes species as an "artificial concept." This is also incorrect, as species are a natural grouping of organisms.
- The fourth option mentions species as a "real unit of classification devised by taxonomists." While this has some truth, it lacks the specificity of being the basic unit.

5. **Conclusion**: The correct answer is that species are considered the "real basic unit of classification."