股票类挂钩理财产品期权不能拆解为( )。

A．认沽行使价

B．认购行使价

C．股票篮子相关性

D．触发区间

Don't hesitate to ______ us if he doesn't ______ in time.[      ]

A. turn to; turn off

B. turn to; turn up

C. turn up; turn to

D. turn down; turn up