有关边界条件的描述，正确的是（ ）

A．He does not feed them with whole carcasses
B．He feeds the tigers at the right time with small pieces of meat
C．He does not feed the tigers with living animals
D．He makes the tigers follow along by whips and ropes

A.偏股型基金
B.偏债型基金
C.股票型基金
D.灵活配置型基金