Final answer:
The boy likely struggles to thank Mrs. Jones because he is ashamed of his actions, reflecting a common theme in literature where characters grapple with shame and remorse while receiving kindness.
Step-by-step explanation:
Based on the excerpts provided, the boy finds it difficult to thank Mrs. Jones likely because b) he was ashamed of his actions. Shame is a powerful emotion that can make expressing gratitude challenging when one feels they have acted wrongly. The excerpts given are thematic of characters struggling with embarrassment, remorse, and the internal conflict that comes with acknowledging one's own faults or shortcomings while receiving kindness or understanding from others. This is evident in instances of characters realizing the impact of their actions on others and feeling remorseful for their past behavior, as well as feeling unworthy or hesitant to accept kindness.