The correct option is B Chloroplast
The process of photosynthesis is carried out in green plastids called chloroplast. Chloroplasts have the light trapping pigment chlorophyll present in the thylakoid membranes organised as grana. The grana are the site of occurrence of light reaction of photosynthesis. The stroma of chloroplast is the site of occurrence of dark reaction of photosynthesis. The dark reaction is actually the synthetic part of photosynthesis during which carbohydrates are synthesized using light reaction.