Final answer:
Claudio and Don Pedro first believe Don John's accusations against Hero, leading to her public shaming during her wedding ceremony in Much Ado About Nothing.
Step-by-step explanation:
In the play Much Ado About Nothing by William Shakespeare, Claudio and Don Pedro initially believe Don John's accusations against Hero. They are easily swayed by Don John's manipulations and false evidence, which leads them to publicly shame and humiliate Hero during her wedding ceremony. Claudio denounces Hero as an unfaithful woman and even wishes for her death, while Don Pedro supports Claudio and does nothing to defend Hero's innocence.