Which prebuilt component can eliminate the need for designing a custom identity verification flow for a marketplace?

Connect Onboarding is the correct choice because it simplifies the process of onboarding users in a marketplace by providing a prebuilt component that handles identity verification and compliance requirements. This tool is specifically designed for platforms that connect sellers and buyers, making it easier to integrate the necessary checks and balances without needing to implement a custom solution from scratch.

By using Connect Onboarding, developers can leverage Stripe's robust infrastructure and compliance measures, ensuring that identity verification is conducted in a secure, efficient, and user-friendly manner. This allows marketplace operators to focus on building their core product features rather than getting bogged down in the complexities of regulatory compliance and identity verification processes.