X线片上判断有无牙槽骨吸收的标准是( )

A．牙槽嵴顶与釉牙骨质界平齐

B．牙槽嵴顶到釉牙骨质界的距离>2mm

C．牙槽嵴顶到釉牙骨质界的距离>3mm

D．牙槽嵴顶到釉牙骨质界的距离<2mm