Answer:
And he was stricken to the heart by the injustice of the suspicion.
Step-by-step explanation:
If I was writing that the theme of "A Piece of String" was that "people will believe what they want to in spite of truth", the passage that would give the best support to my theme would be "And he was stricken to the heart by the injustice of the suspicion."
This is because it directly relates to the given theme.