In cyclic photophosphorylation, the electron released by reaction centre `(P_(700))` is ultimately accepted by

Options

A. ferrdoxin
B. `NADP^(+)`
C. reaction centre `(P_(700))`
D. plastocyanin.

Explanation

To answer the question regarding cyclic photophosphorylation and the ultimate acceptor of the electron released by the reaction center (P700), we can break down the process step by step.

### Step-by-Step Solution:

1. **Understanding Cyclic Photophosphorylation**:
- Cyclic photophosphorylation is a process that occurs in the light-dependent reactions of photosynthesis, specifically involving Photosystem I (PSI), also known as P700 due to its peak absorption at 700 nm.

2. **Absorption of Light**:
- When light energy is absorbed by the chlorophyll molecules in PSI, it excites electrons to a higher energy state. This is the initial step where radiant energy is converted into chemical energy.

3. **Electron Excitation**:
- The excited electrons are then transferred to a primary electron acceptor. In the case of cyclic photophosphorylation, these electrons do not enter the non-cyclic pathway but instead are cycled back.

4. **Role of Cytochromes**:
- The excited electrons are passed along a series of proteins known as the electron transport chain, which includes cytochromes. These cytochromes serve as electron carriers.

5. **Final Electron Acceptor**:
- In cyclic photophosphorylation, the electrons ultimately return to the reaction center (P700) after passing through the electron transport chain. Thus, the final electron acceptor in this cyclic process is the P700 itself.

### Conclusion:
The electron released by the reaction center (P700) in cyclic photophosphorylation is ultimately accepted by P700 after passing through the electron transport chain involving cytochromes.