The outer membrane of chloroplast is

The correct option is A highly permeable to ions and solute
Chloroplasts are the organelle responsible for photosynthesis and are covered by two membranes (outer and the inner membrane). The outer membrane is highly permeable to ions and solutes while the inner membrane is highly specialized for the transport of important proteins.

The disc-like structures called thylakoids which are stacked above one another to form the granum are present in the stroma of the chloroplast. The thylakoid membrane is equipped with chlorophyll.