Explanation
Correct answer: C.
Choice C is the best answer. There’s only one photographer (Adams), and the photos are his, so the singular possessive "photographer’s" is correct. There’s more than one photo, and nothing belongs to the photos, so the simple plural "photos" is correct.
Why the other choices are wrong
Choice A
Choice A is incorrect. This choice uses the singular possessive "photo’s," which isn’t correct. There’s more than one photo, and they don’t possess anything, so the noun should be the simple plural "photos."
Choice B
Choice B is incorrect. This choice uses the simple plural "photographers" and the singular possessive "photo’s," which aren’t correct. There’s only one photographer (Adams) and there’s more than one photo.
Choice D
Choice D is incorrect. This choice uses the simple plural "photographers," which isn’t correct. There’s only one photographer (Adams).