Actually the correct answer is phaeophytin.but according to question it is plastoquinone

The electron transport chain in photosystem II:

Photosystem II (PSII) is a complex protein structure found in the thylakoid membrane of chloroplasts. It is responsible for capturing light energy and transferring it to other molecules in the photosynthetic electron transport chain. The excited electrons from the chlorophyll molecule in PSII are accepted by different electron acceptors, ultimately leading to the production of ATP and NADPH.

1. Excitation of chlorophyll in photosystem II:

When light energy is absorbed by chlorophyll molecules in PSII, it excites an electron in the pigment. This excited electron is then transferred to the primary electron acceptor, a specialized chlorophyll molecule called P680.

2. Electron transfer to primary electron acceptor:

The excited electron from P680 is transferred to the primary electron acceptor, which is a quinone molecule called QA. This transfer occurs via a series of redox reactions, where the electron is passed from one molecule to another.

3. Electron transfer from primary electron acceptor to the plastoquinone (PQ) pool:

The electron from QA is then transferred to a mobile electron carrier called plastoquinone (PQ), which is a quinone molecule embedded in the thylakoid membrane. PQ can accept and release electrons, allowing the transfer of electrons to other components of the electron transport chain.

4. Electron transfer from the PQ pool to cytochrome b6f complex:

From the PQ pool, the electron is transferred to the cytochrome b6f complex. This complex is composed of several proteins, including cytochrome b and cytochrome f. The electron is transferred between these proteins, undergoing redox reactions.

5. Electron transfer from cytochrome b6f complex to plastocyanin:

After passing through the cytochrome b6f complex, the electron is transferred to a small copper-containing protein called plastocyanin. Plastocyanin carries the electron to photosystem I (PSI), where it participates in the production of NADPH.

6. Final electron acceptor:

The final electron acceptor in PSII is not cytochrome-b or cytochrome-f, as mentioned in options a) and b). It is a quinone molecule, which is represented by option c). This quinone molecule accepts the electron from the primary electron acceptor (QA) and transfers it to the PQ pool, initiating the electron transport chain.

Therefore, the correct answer to the question is option c) Quinone.