Answer: Hi! A useful summary of this passage would focus on D (the natural and man-made features of Bali).
Step-by-step explanation: The paragraph shown isn't exploring enjoyable things to do in Bali. Secondly, descriptions of Bali's buildings, in particular, wouldn't be necessary if they could be summarized along with man-made and non-man-made features of Bali. Finally, some facts about traveling to Bali could be nice, but they are also not essential for summarizing the atmosphere of the landscapes Bali has to offer. Thus, D is the best answer.
I hope that this helps you out! Have a good day! :)