Answer:
A. More hydrogen ions inside the membrane than outside it
Step-by-step explanation:
During electron transfer from water molecule to PS II and then through electron transport chain to the PS I pumps the hydrogen ions inside the thylakoid lumen. ATP synthesis is driven by energy of proton concentration gradient that moves the hydrogen ions (protons) from lumen of thylakoid membrane towards the stroma. Hence, ATP synthesis requires presence of more hydrogen ions inside the membrane.