I think it's not a question to test your technical capabilities rather your thought process.
You'll get stuck here, if you think your technical capabilities are everything you have to offer, because they have your resume, they had two hours of interview with you, they know you are technical.
Definitely you need to come up with a bespoke answer. My advice is to have pride and confidence, and tell them why such a confident person will be an investment for their company. Read about the company and their specialities, tell them you can help them.