The type of contract where the buyer incurs opportunity cost but little or no additional cost risk is called______.

A) fixed-price with incentive
B) firm-fixed-price
C) fixed-price with economic price adjustment
D) fixed-price with right of renewal

①欠债5万余元 ②丈夫、儿子相继病逝
③自杀未遂 ④拾荒还债
⑤好心人帮助，还清债务

A．②①③④⑤
B．②③①④⑤
C．③②⑤①④
D．③②①④⑤