Please provide the correct answer to this general accounting problem using accurate calculations.

Riverdale Chocolates uses a standard cost system to track costs for its premium chocolate bars. The materials standard for each bar produced is 3 ounces of cocoa beans at a standard cost of $0.75 per ounce. During November, Riverdale purchased 4,800 ounces of cocoa beans at a total cost of $3,840. Riverdale used all of these cocoa beans to produce 1,500 chocolate bars. What is Riverdale's materials quantity variance for November