— I'll be away on a business trip. Would you mind looking after my pet cat? 　 

— Not at all. ______. 　 [ ]

A. I've no time　

B. I'd rather not

C. I'd be happy to

D. I'd like it

地面上A、B两点间的水平距离为100m，工程图采用1：1000的比例尺，则图上长度为多少？