A. This very insatiability of the photographing eye changes the terms of confinement in the cave, our world.
B. Humankind lingers unregenerately in Plato's cave, still revelling its age-old habit, in mere images of truth.
C. But being educated by photographs is not like being educated by older images drawn by hand; for one thing, there are a great many more images around, claiming our attention.
D. The inventory started in 1839 and since then just about everything has been photographed, or so it seems.
E. In teaching us a new visual code, photographs alter and enlarge our notions of what is worth looking at and what we have a right to observe.
BCDAE
We see a link between statements D and A. D talks about how just about everything has been photographed and A follows it up by mentioning "this insatiability”. Hence DA is the link. This rules out options (a) and (b). We can see that all the statements are talking about photographs of something. Only B introduces the topic of images in Plato's cave. Hence B is the introductory statement. Hence option (c) is the answer.