Exactly how many bonds doesBob have
(1)OfBob's bonds，exactly 21 are worth at least$5,000 each.
(2)OfBob's bonds, exactly 65 per cent are worth less than$5,000 each.
A．条件(1)充分，但条件(2)不充分．
B．条件(2)充分，但条件(1)不充分．
C．条件(1)和(2)单独都不充分，但条件(1)和条件(2)联合起来充分．
D．条件(1)充分，条件(2)也充分．
E．条件(1)和条件(2)单独都不充分，条件(1)和条件(2)联合起来也不充分．