Final answer:
Option (A), Walter Mitty considers wearing a sling to avoid grinning from the garage men, implying he feels embarrassed and seeks a change in their perception of him.
Step-by-step explanation:
In the context of Walter Mitty's words, "The next time, I'll wear my right arm in a sling; they won't grin at me then," we can infer that Walter Mitty is feeling embarrassed by the attention he's receiving that he perceives as negative or condescending. This suggests he is considering feigning an injury to gain sympathy or respect that he feels is lacking. He does not express an explicit intention to avoid the garage, nor does he mention any actual injury to his arm.
The mention of the garage men grinning at him is the cause for his consideration of wearing the sling, which indicates he is mostly bothered by their reaction to him rather than a misunderstanding or decision to avoid future interactions with them.