Answer:
A. It makes it clear that Twain recognizes the value of what Bixby taught him.
Explanation:
It is obvious that Twain recognizes the lesson from Bixby, when he says, "It was a good enough lesson, but learned the hard way." This means he obviously learned his lesson.
A was the correct answer, hope this help :3
My OUTSTANDING friend from school and I sat on a big rock.
As far as I know, this is how adjective phrases work. Please let me know if this was right for you.