A. a photograph of elephants in a forest is your best answer choice.
Note that the report is about "<em>wild elephants</em>".
Using images of taming elephants or any pictures (or drawings) by humans generally don't give a wild vibe to it.
Not B, because it would seem that the elephant had interaction with the human.
Not C, because the "wild" part of the elephant is gone already (the elephant being tamed by humans and used for exhibition)
Not D, because the word "taming" is in there.
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