Originally developed by ancient Hawaiians,
surfing is appealing because of its unusual confluence of adrenaline, skill, and high-paced maneuvering, because of an unpredictable backdrop that is, by turns, graceful and labored, serene and violent, and because of the camaraderie that often develops among people in their common quest to conquer nature.
All that the author is trying to say here is that surfing is appealing because of a bunch of reasons - because of (1), because of (2) and because of (3). The original construction of the sentence conveys it pretty well. Hence (A)
(b) surfing’s appeal is its unusual confluence of adrenaline, skill, and high-paced maneuvering, an unpredictable backdrop that is by turns graceful and labored, serene and violent, and the camaraderie that often develops - 'Originally developed by ancient Hawaiians', which is the introductory modifier, is meant to modify 'surfing' and not 'surfing's appeal'. Based on this we can reject option (B)
(c) surfing’s appeal to people is because of its unusual confluence of adrenaline, skill, and high-paced maneuvering, because of an unpredictable backdrop that is by turns graceful and labored, serene and violent, and developing camaraderie - This repeats the same error as (B)
(d) surfing is appealing because of its unusual confluence of adrenaline, skill, and high-paced maneuvering, because of a backdrop that is unpredictable and that is by turns gracefully and serenely labored and violent, and the camaraderie that often develops - 'a backdrop that is unpredictable' is a long phrase. Instead, a better version is 'an unpredictable backdrop'. Additionally 'an unpredictable backdrop is by turns A and B, C and D,' not 'a backdrop is by turns A, B+C and D.
where A = graceful, B = labored, C = serene and D = violent
Reject
(e) surfing appeals to them because of having an unusual confluence of adrenaline, skill, and high-paced maneuvering, an unpredictable backdrop that is by turns graceful and labored, serene and violent, and the camaraderie that often develops - Not clear as to who/what is having an unusual confluence of adrenaline, skill and high-paced maneuvering - Is it the ancient Hawaiians or the surfing? - Reject