Documentation in a sprint

I had my PSD examen but i have some doubt about a question related to documentation. To be honest i found the question unclear. I don't remember the specific question but it was about which criteria is used to decide if something should be documented every sprint.
One of the answer is "if it's part of the DOD".
According to me this answer is correct. If it's in the DOD, it means the team agrees documentations is necessary.
What do you think ?

Thanks