Which of the following is used to determine item category WKN (Value Contract Item) for general value contracts (WK1)?

Which of the following is used to determine item category WKN (Value Contract Item) for general value contracts (WK1)?
A . Sales document type WK1 and material group VC (Value contract)
B . Sales document type WK1 and value contract material WKM1
C . Sales document type WK1 and item usage VCTR (Value contract)
D . Sales document type WK1 and item category group NORM

Answer: C