Answer: C. Only trusted programmers will be allowed to make changes to the project.
Explanation: Rebecca been a one of the reliable programmer in in her organization who is authorized to work on closed project. If another programmer is to be allowed to make changes in the project, it have to be "a trusted and reliable programmer ".
To avoid programming manipulation, reliable and trusted programmers are sort after for closed source programming project.
Closed source software holds encrypted and safe source code, so that user can not modify, copy or delete without consequence.