Answer (C) is correct.
A standard cost is an estimate of what a cost should be under normal
operating conditions based on studies by accountants and engineers. In
addition, line management is usually involved in the setting of standard
costs as are quality control personnel. Top management would not be
involved because cost estimation is a lower level operating activity.
Participation by affected employees in all control systems permits all
concerned to understand both performance levels desired and the
measurement criteria being applied.