Cytochrome C (small protein) is attached to outer surface of the inner mitochondrial membrane.

Answer

**Step-by-Step Solution:**

1. **Understanding the Role of Cytochrome C**: Cytochrome C is a small protein that plays a critical role in the electron transport chain (ETC) within mitochondria. It is involved in the process of cellular respiration, specifically in the transfer of electrons.

2. **Locating Cytochrome C**: Cytochrome C is located on the outer surface of the inner mitochondrial membrane. This positioning is crucial for its function in the electron transport chain.

3. **Electron Transport Chain Overview**: The electron transport chain consists of several complexes (I to IV) and mobile carriers. Cytochrome C acts as a mobile electron carrier between Complex III and Complex IV.

4. **Function of Cytochrome C**: In the electron transport chain, electrons are transferred from NADH and FADH2 through various complexes. Cytochrome C accepts electrons from Complex III and donates them to Complex IV, facilitating the reduction of oxygen to water.

5. **Conclusion**: Given the information about the location and function of Cytochrome C, the statement "Cytochrome C (small protein) is attached to the outer surface of the inner mitochondrial membrane" is true.

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