Your best answer would be A. Will have finished.
Somthing went wrong when i put the answer in so ill comment it
It depends in what sort of " powerful " you mean. They could have power in being wealthy if they're a good singer/actor. But I doubt celebrities are powerful in anything else except for maybe fundraising and things that help other people out. Some celebrities could be powerful in getting high as well.
We can practice in the park nicely.
Pretty sure it's A. Since it explains what the manual is all about to begin with.