Should I take the October or November SAT IIs if I am applying ED?

I was planning on applying ED to UPenn SEAS and on their website, it says that the last available date they will accept SAT subject tests is from November.

It also mentions that “The University of Pennsylvania reserves the right to evaluate an application and render a final decision even if all pieces of the application have not been received.”

Would it be a huge risk if I took the November test? (Would my scores be sent in time?)

You need to send your scores directly, meaning you can’t wait to see what your score is before you send them. It
isn’t really a “huge risk” because Subject Tests are recommended not required anyway.