He's talking morals after abandoning his wife in a roadside diner.
He tells the anecdote of his mother because he thinks the boy is wrong for fleeing his mother. It's not ironic since Mr. Shiflet does it on purpose. Ironically, he is blaming himself for abandoning his mother, who was a divine gift. He recently left his wife at a diner. He should know better than to abandon people...
All of them because they don't have capital letters at the start.
Joking apart, the real answer is C, because it doesn't have a comma. It should read "For at least three hours, Melissa has been singing the same song.
Wouldn’t we need to see the 2 passages in order to answer?