The most abundant protein in chloroplast is:

Explanation

Carbon dioxide fixation in dark reaction is carried out by the enzyme Ribulose bisphosphate carboxylase, also known as Rubisco. It is the most abundant protein in chloroplasts, and probably the most abundant protein on earth. B.It is a 5 carbon( ketoses) carbohydrate and not protein. C.It is a 5 carbon sugar (carbohydrate) used in dark reaction of photosynthesis. D.It is a complex in thylakoid membrane acting as electron carrier.