Client Claiming Ownership of Code I Wrote as Freelancer

Looking for advice on this situation. Client Claiming Ownership of Code I Wrote as Freelancer What would you do?

Details: I'm in a situation where I need to understand my legal options. Has anyone dealt with something similar?

Update: Thanks everyone for teh guidance. I consulted with an attorney and we're moving forward. The advice here helped me understand what questions to ask and what to expect. Will update when there's a resolution.