Explanation
Correct answer: B.
Choice B is the best answer because it most logically completes the text’s discussion of visual balance in photography. In this context, "contingent on" means conditional upon, or determined by. The text indicates that different ways of balancing elements in a photograph convey different ideas to viewers (for example, symmetrical composition tends to emphasize similarity among elements, whereas asymmetry tends to emphasize difference). Thus, there is a strong connection between what a photograph conveys and how its elements are balanced. Therefore, what a photo conveys is contingent on how it is balanced.
Why the other choices are wrong
Choice A
Choice A is incorrect. In this context, "inhibited by" most nearly means hindered or undermined by. The text indicates that different ways of balancing elements in a photograph convey different ideas to viewers, thereby indicating a relationship between image balance and what is conveyed. Although this explanation is consistent with a photographer choosing asymmetrical balance even while intending to convey similarity (associated with symmetrical balance), there is nothing to indicate that messages generally are inhibited by balance. Rather the implication is that balance is a tool photographers can use to craft their messages.
Choice C
Choice C is incorrect. In this context, "obligated to" means duty bound toward or answerable to. In context, it would not make sense to assert that a photograph’s message is obligated to how that photograph is balanced.
Choice D
Choice D is incorrect. In this context, "reserved for" most nearly means solely available to someone or held aside for some purpose. The text as a whole does not support the claim that a photograph’s message is reserved for how that photograph is balanced.