Which of the following is not one of the responsibilities of the Tariff Commission ( )

A．To formulate the guideline for drawing up the regulations

B．To set temporary tariff rates

C．To levy Customs tariffs on imports & exports

D．To examine the draft of the amendment to tariff

某优选股面值1000元，发行价格1100元；发行成本4%，每年付息一次，固定股息率6%，所得税税率为30%，则优选股的税前资金成本为( )。

A．6.2%

B．7.1%

C．8.1%

D．9.0%