A manager of a product development project reviews the results of the concept validation performed by the team. By showing some concepts to consumers, the team discovered an additional need and now wants to add it to the needs document. However, the manager argues that the identification of customer needs is long over and thus should not be changed. Which statement is correct? 

a. Once the customer needs are documented, they should not be revisited. 

b. Product development is an iterative process, and it is common that activities are repeated. 

c. Neither of these statements is correct.