Her sister left home in1998, and       since.

A．had not been heard of

B．has not been heard of

C．had not heard of

D．has been heard of

老王两年前投资的一套艺术品市价上涨了50%，为尽快出手，老王将该艺术品按市价的八折出售，扣除成交价5%的交易费用后，发现与买进时相比赚了7万元。问老王买进该艺术品花了多少万元？

A.84 

B.42 

C.100 

D.50