执行MOV AX，WDAT指令时，要使AX寄存器中内容为3412H，不能采用( )数据段定义。

A．DSEG SEGMENT WDAT EQU WORD PTR BDAT BDAT DB 12H，34H DSEG ENDS

B．DSEG SEGMENT BDAT DB 12H，34H WDAT = WORD PTR BDAT DSEG ENDS

C．DSEG SEGMENT WDAT EQU THISWORD BDAT DB 12H，34H DSEG ENDS

D．DSEG SEGMENT BDAT DB 12H，34H WDAT LABEL WORD DSEG ENDS