General rules for changing direct speech into indirect speech. Omit all inverted commas or quotation marks. End the sentence with a full stop. If the verb inside the inverted commas/quotation marks is in the present tense, change it into the corresponding past tense.
I don’t know what the author wrote because so don’t have a picture or context
I would go with:
A theme is best written as statement because a theme is main thing of a story, the author could also use a statement in a story to make it seem more alive or more real.
I Hope my answer worked for you :)
