The correct option is B Grana
Chlorophyll is the light trapping pigment found in the chloroplast of green plants. Chloroplasts are structurally made up of two components- thylakoids (internal membrane structures) and stroma. Some of the thylakoid membranes are stacked one above the other and are called as grana. The grana contain light trapping pigment chlorophyll and are thus the site of light reaction. The stroma contains enzymes, which are responsible for dark reaction part of photosynthesis.