In American Federation of Government Employees, AFL-CIO V

In American Federation of Government Employees, AFL-CIO v. Robert M. Gates, Secretary of Defense, the issue arose out of a contentious dispute over the collective-bargaining rights of hundreds of thousands of civilian employees of the Department of Defense (DoD) . What authority of the National Defense Authorization Act (NDAA) authorizes the DoD to curtail collective bargaining rights that DoD's civilian employees otherwise possess under the Civil Service Reform Act of 1978?

A) Collective authority
B) Relative authority
C) Temporary authority
D) Absolute authority