单选题The seller was trying to sign a substantial order（）A that is made with certain conditions.B that you have finalized the delivery dates. C then he could get a large discount.D to be more flexible over terms of payment.
题目
单选题
The seller was trying to sign a substantial order（）
A
that is made with certain conditions.
B
that you have finalized the delivery dates.
C
then he could get a large discount.
D
to be more flexible over terms of payment.