Practice exam question regarding substitution

Can you please clarify the answer below?
The questions specifically says that the substitution will require revision to the contract documents.
Thank you

A fast-tracked project has begun construction and the contractor has submitted a substitution request for a critical path item. This substitution would require a revision to the contract documents.
What is the next step for the architect after receiving this request from the contractor?

Hi Yvette - There are certain additional services that can and should be performed during CA, before receiving owner approval, in order to not delay the project. This situation is one of them, and it’s covered in AIA B101, article
I’ve also edited your comment to remove the text of this question - posting of paid content on the community is not allowed.

Thank you, I thought this is where we can ask questions.

It definitely is! We just ask that you don’t post the entire question here. Feel free to ask about the underlying concept of the question or about what particular part of it you had trouble with.