以下关于库存单位、采购单位说法正确的是（）？

A.品号库存单位和采购单位可设置为不相同

B.品号库存单位和采购单位必须是一样的

C.采购单位在设置公用参数中设置

D.以上都不对

At all angles of inclination, the metacenter is（）.

A.vertically above the center of buoyancy

B.vertically above the center of gravity

C.at the intersection of the upright vertical centerline and the line of action of the buoyant force

D.at the geometric center of the underwater volume