Graphic Analysis of Incurred and Locked-In Costs Provides Several Insights

Graphic analysis of incurred and locked-in costs provides several insights as to how the different concepts influence decisions. Which of the following statements is FALSE?

A) Costs are generally locked in before they are incurred.
B) After a product's design has been approved, costs are difficult to influence.
C) When and how costs are locked in are more important than when and how costs are incurred.
D) Most costs are locked in during the manufacturing process.