【单选题】

Quality and grade are not the same. A fundamental distinction is that ______ .
A．grade is a category assigned to products or services having the same functional us but different technical characteristics

B．low quality may not be a problem; low grade is always a problem
C．determining and delivering the required levels of quality are not included in the responsibilities of the project manager and the project team
D．determining and delivering the required levels of grade are not included in the responsibilities of die project manager and the project team