The correct sequence of flow of electrons in the light reaction is:
| 1. | PS II, plastoquinone, cytochromes, PS I, ferredoxin |
| 2. | PS I, plastoquinone, cytochromes, PS II, ferredoxin |
| 3. | PS I, ferredoxin, PS II |
| 4. | PS I, plastoquinone, cytochromes, PSII, ferredoxin |
