Assuming all boxes are of the same size and all products being filled in are also the same size. B is correct. Since it is the same operator or the same machine packing the boxes, it is a repeatability issue. Reproducibility involves another operator packing or using a different similar machine to pack. While both accuracy and repeatability are important, repeatability tends to be more important than accuracy in many applications. You can have accurate results that are not repeatable and repeatable results that are not accurate. Accuracy is how close a measurement is to the true value, while repeatability is the measurement of the ability to subsequently hit the same target value or result.