a. They argued for the establishment of national parks and forests.
b. They defended the efficiency of big business.
c. They honestly portrayed human misery and the struggles of common people.
d. They encouraged social reform based on the teachings of the Bible.
I’m thinking A, am i right?
Yes, (a) is really the only one that goes along with the naturalism, which is the belief that all religious truth comes from nature or natural processes. Naturalists would have opposed big business (b), not been overly concerned about (c), and would probably have rejected Biblical teaching.
Hope this helps 🙂