Answer:
fluid space that contains DNA, ribosomes, and other enzymes
Step-by-step explanation:
B is points towards the "empty" space, meaning its Stroma.
Stroma defintion: involved in the synthesis of organic molecules from carbon dioxide and water or the fluid of the chloroplast surrounding the thylakoid membrane;
Let's look at the answer choices.
A. enclosed space containing proteins used in ATP formation
B. membranes enclosing open space
C. layered stacks of membranes
D. fluid space that contains DNA, ribosomes, and other enzymes
Obviously not C.
A is Synthase.
B is the whole thing.
It is D.
(BTW THIS IS MATH!! Not science!! Just in case you have more questions!)