I ______have come here in time, but I met an old friend of mine. I stopped and talked with him for some time.

A．shouldn’t

B．must

C．needn’t

D．could

证券交易所债券质押式回购交易中，以券融资方在初始交易前，必须将足够的资金存入其委托的证券经营机构的证券清算账户。( )