Anaerobic respiration is

Options

A. Complete oxidation
B. Incomplete oxidation
C. Anabolic reaction
D. Fermentation

Answer

### Step-by-Step Solution

1. **Understanding Anaerobic Respiration**:
- Anaerobic respiration occurs in the absence of oxygen. It is a type of respiration that does not involve the use of oxygen to convert glucose into energy.

2. **Identifying the Options**:
- The options provided are:
- A) Complete oxidation
- B) Incomplete oxidation
- C) Anabolic reaction
- D) Fermentation

3. **Analyzing Each Option**:
- **Complete Oxidation**: This refers to the full breakdown of glucose in the presence of oxygen, which is characteristic of aerobic respiration. Therefore, this option is incorrect.
- **Incomplete Oxidation**: This typically refers to the partial breakdown of glucose without oxygen, but it is not the main characteristic of anaerobic respiration. Thus, this option is also incorrect.
- **Anabolic Reaction**: Anabolic reactions involve the synthesis of complex molecules from simpler ones, which is not the primary function of anaerobic respiration. While anaerobic respiration does involve some synthesis, it primarily focuses on energy production. Therefore, this option is not the best fit.
- **Fermentation**: This is a specific type of anaerobic respiration where organic substances (like glucose) are converted into acids or alcohols, along with a small amount of energy. This process occurs without oxygen and is the most appropriate description of anaerobic respiration.

4. **Conclusion**:
- Based on the analysis, the most suitable answer to the question "Anaerobic respiration is" is **D) Fermentation**.