Answer:
Like other reader interpretations, it must be supported with evidence from the text.
Step-by-step explanation:
The purpose of a text often depends on who is interpreting the text or document, so the theme, motif and purpose should be backed or supported by evidence from the text, otherwise it would become too subjective to the opinion of whomever is trying to interpretate the text. So the best answer to the question would be "Like other reader interpretations, it must be supported with evidence from the text."