Your program manager has just returned from a class on program/project management and is filled with ideas. He seems to be using the terms fast tracking and concurrent engineering interchangeably. You try to explain the primary difference by stating:

a. fast tracking is about overlapping activities while concurrent engineering is moving implementers to an earlier phase of the project

b. fast tracking is overlapping activities while concurrent engineering is adding resources to the critical path

c. fast tracking is about moving implementers to an earlier phase of the project while concurrent engineering is about adding resources to the critical path

d. fast tracking is overlapping phases while concurrent engineering is overlapping activities