The important detail that the photograph best helps readers understand is C) "Parthenon, high on a hill, catches the first light of morning."
This refers to the use of evidence to best validate a claim to make them understand better.
Hence, we can see that based on the given text and from the complete information, there is an image that shows a structure and this is related to the text and acts as a supporting detail as it describes Parthenon which is option C.
Read more about supporting details here:
https://brainly.com/question/884525
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