______ asked to help me with my lessons, he always refused, saying he was too busy.

A．Whatever

B．Whenever

C．Whoever

D．However

（）是指法人账户透支业务中客户透支额度生效后，华夏银行因为要为客户备付用于透支的资金而向其收取的费用。

A.备付手续费

B.透支额度

C.透支利息

D.透支承诺费