I need help solving this Management Accounting question

6.15 KL Processing Limited has identified that an abnormal gain of 160 litres occurred In Its refining process last week. Normal losses are expected and have a scrap value of 2.00 per litre. All losses are 100 per cent complete as to material cost and 75 per cent complete as to conversion costs. The company uses the weighted average method of valuation and last week's output was valued using the following costs per equivalent unit: Materials 49,40 Conversion costs 11.20 The effect on the profit and loss account of last week's abnormal gain is: (a) Debit 2528 {b} Debit 12828 (c) Credit 12528 c) Credit 2848 e) Credit 3158 CHA Stage 2