In a 12-bit Hamming code with codeword bits numbered from position 1 to position 12 (right-to-left):
Bit PositionBitValue12d8111d7110d609d5x8c8y7d406d315d204c403d112c211c10
Using even parity for the check bits:
Parity bit c1 covers all positions with the 1st bit of their binary index as 1 (positions 1, 3, 5, 7, 9, 11):
c1=d1⊕d2⊕d4⊕d5⊕d7 Substitute the given values (c1=0,d1=1,d2=0,d4=0,d5=x,d7=1):
0=1⊕0⊕0⊕x⊕1 0=x⟹x=0 Parity bit c8 (y) covers all positions with the 4th bit of their binary index as 1 (positions 8, 9, 10, 11, 12):
c8=d5⊕d6⊕d7⊕d8 Substitute x=0,d6=0,d7=1,d8=1:
y=0⊕0⊕1⊕1=0
Thus, x=0 and y=0, which matches option (A).