Rather than use a WBS, your team developed a bill of materials to define the project’s work components. A customer review of this document uncovered that a scope change was needed, because a deliverable had not been defined, and a change request was written subsequently. This is an example of a change request that was the result of—

a. An external event

b. An error or omission in defining the scope of the product

c. A value-adding change

d. An error or omission in defining the scope of the project