During photosynthesis, ATP is generated when protons flow
- A
Out of the chloroplast across the outer envelope membrane
- B
Through photosystem II reaction-center channels into the lumen
- Ccheck_circle
From the thylakoid lumen into the stroma through ATP synthase
- D
From the stroma into the thylakoid lumen through ATP synthase
Explanation
Light reactions pump H⁺ into the lumen, building a gradient. ATP synthase lets H⁺ flow back to the stroma, driving ATP production.