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.
Both of theese preamble and constitution are constant. I meen they can't be changed at all
He found his next door neighbor was funny and friendly.
Celebration? In not sure but wouldnt you celebrate all of these?