Which of the following statements concerning coupon rate structures is FALSE （）

A. Step-up notes have coupon rates that increase over time at a pre-specified rate.

B. Accrual bonds have only one cash inflow at maturity.

C. Accrual bonds, like zero-coupon bonds, always sell at a discount to face value.

乘务员空中用餐应在餐饮服务结束后，时间尽量控制在（）分钟以内，飞行关键阶段禁止用餐。

A.20

B.25

C.10