Which of the following would be true about earned value for a project that has been under control over the duration of the project? It starts out at zero and increases towards the end of the project at which time earned value should equal the total budget value of the project.

a. It should always be less than actual value

b. It declines over the course of the project

c. it does not change over the course of the project as long as

d.the project in on schedule.