Process costing

I would to ask how to find input value for the below question given : a company uses process costing to value output, during the last month the following information was recorded : output : 2800 kg value at $7.50/kg normal loss: 300kg which has scrap value of $3/kg actual loss:200kg what was the value of the input? A$22650 B$21900 C$21600 D$21150 thank you