单项选择题

The existing law states that ______.

A.convictions can be made on confessions and statements taken by police officers from accused persons are valid legal evidence
B.convictions can' t be made on confessions alone and there should be a third party when taking statements from accused persons
C.convictions can be made on confessions and a third party should be present when taking statements from accused persons
D.convictions can' t be made on confession alone and the statements taken by police officers from accused persons are valid legal evidence