问题详情

Accordingtothepassage,underwritingsimplymeans______.
A．thattheinvestorpromisestobuythesecurities
B．thattheinvestmentbankerpromisestosellthesecurities
C．thattheinvestmentbankerpromisestobuythesecurities
D．thattheinvestorpromisestosellthesecurities

请帮忙给出正确答案和分析，谢谢！