B$.100411$

C$.$ Or$$CH

D$.$ OFFAH

$21.$ In $8086,$ the two segment registers that are used with pointers IP and SP to generate pl register respectively.

A$.$ DS$,$ ES

B$.$ ES$,$ SS

C$.$ CS$,$ sS

D$.$ CS$,$ DS

$22.$ What is the binary form of decimal number $51?$

A$.110011$

B$.11110$

C$.110111$

D$.100000$

$23.$ What is the hexadecimal form of binary number $101111rB?$

A$.5DH$

B$.5FH$

C$.6DH$

D$.7EH$

$24.$ Let $a=00111001B,b=11110011B,$aANDb is

A$.00000111B$

B$.01111101B$

C$.00110001B$

D$.1111110$

$25.$ Let $a=00111000B,b=11110010B,a$ OR $B$ is

A$.11111010B$

B$.00001111B$

C$.11110000B$

D$.11010$

II$.$ Short Answer Questions $($There are $4$ points for each question and problem$)($Score: $)$

After the following instructions are executed, what are the content in BX$?$

XOR AX$,$ AX

MOV BX$,2$

MOV CX$,"4$

MOV DX$,3$

$39$