Question

the place where the light reactions happen in the chloroplast.. thylakoid inner membrane grana stroma

Explanation:

In chloroplasts, light reactions occur in the thylakoid membrane. Thylakoids are membrane - bound compartments within chloroplasts. Grana are stacks of thylakoids. The inner membrane of chloroplasts is not the site of light reactions. The stroma is the fluid - filled space outside the thylakoids where the Calvin cycle (dark reactions) occurs.

Answer:

Thylakoid