What is the reason for this?

You need to configure sales phases during fine tuning but an activity is in read-only mode.

What is the reason for this? Please choose the correct answer.
A . The Fine Tuning activity is NOT open for configuration.
B . The Fine Tuning activity is NOT added to the project.
C . The Corresponding scoping element is NOT activated.
D . The Fine Tuning activity is closed.

Answer: C