Waiting until the product is nearly launched before involving customer validation is a known anti-pattern. To avoid late-stage surprises, validation should be integrated continuously throughout the lifecycle. This aligns with the Agile principle of customer collaboration and feedback loops.
According to PMBOK Guide - Seventh Edition, early and continuous engagement of stakeholders (especially customers) helps in detecting issues early. Frequent validation allows incremental improvements and reduces risk of rework at later stages.
Option A is reactive and not preventive.
Option C is helpful but not sufficient without continuous validation.
Option D focuses on internal quality but not customer-centric validation.
References:
PMBOK Guide - Seventh Edition, Stakeholder and Delivery Performance Domains Agile Practice Guide, Chapter 5: "Customer Involvement and Continuous Feedback"