John's aversion to playing on the rockpile likely stems from the fact that he knows Gabriel seeks excuses to scold and beat him because he's not his biological son; conversely Roy knows his father favors him and this favor allows him to entertain his fascination with the rockpile and dare to play on it in defiance of his mother's instructions.
Explanation: Most young laborers are not happy about their job and/or their work. Conditions are very harsh and most workers get little amounts of money, So D. Happily delivered is the correct answer. :)