What role does sarcasm play in pride and prejudice?

Does anyone know the answer to the question?

Which statement from chamberlain's speech to parliament did the least to support his cause? a. "no doubt i shall have plenty of critics who will say that i am guilty of facile optimism . ." b. "the house will remember that when i last addressed them i gave them some account of the godesberg memorandum . ." c. "therefore, it was essential that we should quickly reach a conclusion . ." d. "the relief that our escape from this great peril of war has, i think, everywhere been mingled in this country with a profound feeling of sympathy . ."

Which of the following excerpt from part one of trifles suggest that mrs.hale believes mrs.wright may have had a motive for killing her husband?