Since the premium varies with the scope of ______, extra premium is for buyer's account, should additional risks be covered.
A、assurance
B、insurance
C、business
D、enterprise
【正确答案】：B
【名师解析】:题目中提到的"premium"通常指的是保险费用，而"the scope of ______"则是指保险的范围。根据题目的语境，额外的保险费用是因为买家需要额外的风险覆盖，这表明"premium"与"insurance"紧密相关。选项A "assurance"通常指保证或确信，选项C "business"指商业，选项D "enterprise"指企业或事业，它们都与保险费用的上下文不符。因此，正确答案是选项B "insurance"，它与题目中的"premium"和"additional risks"直接相关。
