The correct option is D a4(b2−c2)+b4(c2−b2)+c4(a2−b2)
Here we have to follow the options one by one:
in A
⇒a4(b2−c2)+b4(c2−b2)+c4(a2−b2)
⇒a4(b2−c2)−b4(b2−c2)+c4(a2−b2)
⇒(a4−b4)(b2−c2)+c4(a2−b2)
⇒(a4−b4)(b2−c2)+c4(a2−b2)
⇒(a+b)[(a−b)(a2+b2)(b2−c2)+c4(a−b)] (since, a4−b4=(a2−b2)(a2+b2))