They prepared THEMSELVES for the next examination, the capitalized word THEMSELVES is:
They prepared THEMSELVES for the next examination, the capitalized word THEMSELVES is:
Explanation
"THEMSELVES" is a reflexive pronoun used here to indicate that the action of preparing is directed back at the subject "they."
Reflexive: Reflexive pronouns are used when the subject and the object of the verb are the same, and they often end in "-self" or "-selves" (e.g., "myself," "yourself," "themselves").