Which sentence from “The Treasure of Lemon Brown” best helps readers understand Greg's father?

Greg sat in the small, pale green kitchen listening, knowing the lecture would end with his father saying he couldn’t play ball with the Scorpions.
His father had been a postal worker for all Greg’s life, and was proud of it, often telling Greg how hard he had worked to pass the test.
He thought ahead of what his father would say and wondered if he should tell him about Lemon Brown.
Greg pushed the button over the bell marked Ridley, thought of the lecture he knew his father would give him, and smiled.