Which of the following passages best experiences Mark Twain's purpose in " A Cub Pilot"

As the boy steamboat pilot on the Mississippi River, Mark Twain was taught a useful, but challenging, showing by the skilled pilot, Mr. Bixby. Mr. Bixby asked Mark if he knew enough to get this boat across the closed path. Knowing that there cost a lot of food at this line and no possibility of going aground, sign responded that indeed he would, since “I wouldn't go lower there with a church steeple.†Mr. Bixby replied, “You think So, do you? € Something in Mr. Bixby's voice shook Mark's confidence, which Mr. Bixby's leaving Mark alone in the pilothouse did nothing to restore. This path did not go smoothly.

Answer: As the boy steamboat pilot on the Mississippi River, Mark Twain was taught a useful, but challenging, showing by the skilled pilot, Mr. Bixby.