The project lead must investigate the client's claims to assess the validity of the concerns and the associated penalties. Engaging in fact-finding and documentation review is the first step. If there's a dispute, negotiation should follow. This approach aligns with the PMBOK Guide's guidance on issue management and stakeholder engagement. Option A is premature and accepts liability without due diligence. Option C bypasses the client's concern. Option D deflects the responsibility and delays resolution. References: PMBOK Guide - Seventh Edition, Stakeholder and Delivery Performance Domains PMBOK Guide - Sixth Edition, Section 13.3: Manage Stakeholder Engagement -