NADH is oxidised to `NAD^(+)` rather slowly in fermentation, however the reaction is very vigorous in case of aerobic respiration

Answer

### Step-by-Step Solution:

1. **Understanding Respiration**:
- Respiration is a biochemical process where energy is released from organic molecules, primarily glucose, through the breaking of chemical bonds.

2. **Types of Respiration**:
- There are two main types of respiration:
- **Aerobic Respiration**: Occurs in the presence of oxygen.
- **Anaerobic Respiration (Fermentation)**: Occurs in the absence of oxygen.

3. **Aerobic Respiration Process**:
- In aerobic respiration, glucose is broken down into pyruvate during glycolysis.
- When oxygen is available, pyruvate enters the mitochondria and undergoes further oxidation in the Krebs cycle, leading to the production of ATP and other high-energy molecules.

4. **Anaerobic Respiration Process**:
- In anaerobic respiration, glucose is also converted into pyruvate through glycolysis.
- However, in the absence of oxygen, pyruvate is converted into either lactate (in animals) or ethanol and carbon dioxide (in yeast), which is known as fermentation.

5. **NADH Oxidation**:
- In aerobic respiration, NADH (the reduced form of NAD+) is oxidized back to NAD+ very efficiently during the electron transport chain, which is a vigorous process.
- In fermentation, the oxidation of NADH to NAD+ occurs more slowly because it relies on the conversion of pyruvate to lactate or ethanol, which does not involve the electron transport chain.

6. **Conclusion**:
- The statement that "NADH is oxidized to NAD+ rather slowly in fermentation" is correct, as fermentation is less efficient in regenerating NAD+ compared to aerobic respiration, where the process is vigorous.