Question

based on the diagram, where are hydrogen ions found within a chloroplast?
a. in the thylakoids only
b. in the electron transport chains only
c. in the electron transport chains and the photosystems
d. in the stroma and the thylakoids

Explanation:

During the light - dependent reactions of photosynthesis in chloroplasts, hydrogen ions are pumped into the thylakoid space from the stroma. Also, hydrogen ions are present in the stroma. The diagram shows hydrogen ions ($H^+$) both inside the thylakoids and in the surrounding stroma area.

Answer:

D. In the stroma and the thylakoids