What notable change occurs in Dunny after his military service?

After his military service, Dunny experiences significant personal transformation, particularly in his relationship with Mary Dempster. This relationship, which is complex and pivotal throughout the narrative, undergoes a notable shift after the war. Dunny’s time in the military exposes him to profound experiences that deepen his understanding of life, spirituality, and his own identity. When he reconnects with Mary, who represents a kind of spiritual guide or muse, he gains insight into his past and grapples with the implications of her saintly presence in his life. This reconnection prompts Dunny to reflect on themes of love, guilt, and redemption, which are central to his character development.

The other options, while they involve significant aspects of Dunny's life, do not capture the essence of the transformation he undergoes post-service as effectively as his relationship with Mary Dempster does. His journey as a teacher or involvement in corporate life, although important in other contexts, do not encapsulate the depth of his emotional and spiritual growth triggered by reconnecting with Mary.