Explanation
Correct answer: C.
Choice C is the best answer because it most logically completes the text’s discussion of carte de visite photos. To "popularize" a technology is to allow it to be used and appreciated widely. The text explains that unlike the photos produced by earlier forms of photographic technology, carte de visite photos were inexpensive and could easily be obtained by "everyday people," who enjoyed exchanging the images. Therefore, carte de visite photos helped popularize photography.
Why the other choices are wrong
Choice A
Choice A is incorrect because the text indicates that instead of weakening the emerging technology of photography, carte de visite photos allowed it to be more widely accessed and enjoyed by people.
Choice B
Choice B is incorrect. The text establishes that large numbers of people enjoyed using carte de visite photos, so it can be inferred that these photos caused photography to be praised, or celebrated. However, it wouldn’t make sense to say that inanimate objects—in this case, photos—had praised photography; instead, carte de visite consumers themselves would have praised it.
Choice D
Choice D is incorrect because the text explains that rather than isolating photography, or limiting its availability, carte de visite technology made photography more widely accessible to people.