閱讀下列程序段，注釋指令中計(jì)算符LENGTA的取值. 
DATA     SEGMENT 
A        DW     10 DUP（？）， 1234H，  20 DUP（？） 
B        DB    ‘ABCDEF’，6 DUP（？） 
C        DW     10， 20 DPU（？） 
D        DW     5 DUP（3 DUP（2），5） 
DATA     ENDS                ┆ 
①       MOV     AX， LENGTH  A 
②       MOV     BX ，LENGTH  B 
③       MOV     CX ，LENGTH  C 
④       MOV    DX ，LENGTH  D