Answer: The correct answer for the blank is-
B. chloroplasts.
Chloroplast is a specialized membrane bound organelle that is present in photosynthetic organisms such as green plants and algae.
It contains a green colored pigment ( chlorophyll) that absorbs energy from sunlight ( in the presence of carbon dioxide and water) and converts it into chemical energy in the form of ATP and NADPH, which is further utilized in the formation of food ( glucose). This process is called photosynthesis.
Thus, chloroplast is considered as the site for photosynthesis.
Therefore, upper palisade layer of leaves contain more chloroplast to carry out photosynthesis as compared to other parts of the plant.
Thus, option B) is the right answer.
