In a manufacturing firm, the standard quantity of material was set at 10 kg and standard price was fixed at Rs. 2 per kg. The actual quantity consumed was 12 kg and the actual price paid was Rs 1.90 per kg. Determine material usage variance.

• A. Rs 4 favorable
• B. Rs 4 unfavorable
• C. Rs 2.80 unfavorable
• D. Rs 1.20 favorable