What Would a Favourable Sales-Quantity Variance MOST Likely Be Caused

Multiple Choice

What would a favourable sales-quantity variance MOST likely be caused by?
Variant question

A) A new competitor providing better service in the high-margin product sector
B) The company offering low-margin products at a higher price
C) A competitor having distribution problems with high-margin products
D) The company experiencing quality-control problems that get negative media coverage of low-margin products