The correct option is C 4a2b2c2
△ = ∣∣
∣
∣∣b2+c2a2a2b2c2+a2b2c2c2a2+b2∣∣
∣
∣∣=−2∣∣
∣
∣∣0c2b2b2c2+a2b2c2c2a2+b2∣∣
∣
∣∣, by R1 → R1−(R2+R3)=−2∣∣
∣
∣∣0c2b2b2a20c20a2∣∣
∣
∣∣, by R2 → R2−R1R3 → R3−R1=−2{−c2(b2a2)+b2(−c2a2)} = 4a2b2c2.
Trick: Put a=1, b=2, c=3, so that the option give different values.