AL - 3AH.
BL - 49H
The given instruction is to subtract the contents of BL from AL.
0011 1010 -
0100 1001
---------------------
1111 0001
Sign flag S=1
Carry flag CY=1
result= F1H
Sign flag is set since the produced result is negative.
Since the first operand is less than the second operand, the carry flag is set.