I would like to order three RC 720s ___________ and, at the same

I would like to order three RC 720s ___________ and, at the same time, establish similar terms for future purchases up to $2,500 monthly.
A、for sixty-day credit days
B、in sixty-day credit days
C、on sixty-day credit terms
D、for sixty-day credit terms
【正确答案】：C