MacDuff is a fast food restaurant specialises in vegan burgers. It sells a variety of burgers with different

pries and a range of side dishes. Most of MacDuff's employees are part time casual workers. In the last

quarter, the management of MacDuff discovers a significant favourable direct material variance. Which of

the following is a likely cause this variance?

Successful negotiations with labor union such that workers are no longer paid overtime on

weekends

Management setting an incorrect standard for raw materials

An unexpected increase in burger sales due to increasing prices by a competitor.

A fall in the prices of salt and pepper which are added to all burger patties