Final answer:
The structure formed by the reaction center, antenna molecules, and primary electron acceptors in the thylakoid membrane is called Photosystem II (PSII).
Step-by-step explanation:
The structure formed by the reaction center, antenna molecules, and primary electron acceptors clustered in the thylakoid membrane is called Photosystem II (PSII). PSII is one of the two major components of the photosynthetic electron transport chain, which also includes the cytochrome complex. It is responsible for capturing light energy and initiating the flow of electrons.