If 
then (a3 – b3) = ?
It is given in the question that,
a2 + b2 = - ab
a2 + b2 + ab = 0 (i)
We know that,
a3 – b3 = (a – b) (a2 + b2 + ab)
From (i), we have a2 + b2 + ab = 0
∴ a3 – b3 = (a – b) × 0
a3 – b3 = 0
Hence, option D is correct
11
If then (a3 – b3) = ?
It is given in the question that,
a2 + b2 = - ab
a2 + b2 + ab = 0 (i)
We know that,
a3 – b3 = (a – b) (a2 + b2 + ab)
From (i), we have a2 + b2 + ab = 0
∴ a3 – b3 = (a – b) × 0
a3 – b3 = 0
Hence, option D is correct