Answer: C. His reputation for clever dealing betrays him when he tells the truth.
The statement in letter c shows irony because it presents contrasting events. Mr. Hauchecorne is a clever person however the irony strikes on him when nobody believes him and makes fun of his cleverness when he said the truth about the string.
I blame you (with a passive voice)
I believe its a metaphor.
C or A! Probably c though!
