1, 2, 3, 4…………….When y = 0⇒ (Y3 - y) = y(y2 - 1) = 0When y = 1⇒ (y3 - y) = y(y2 - 1) = 0When y = 2⇒ (y3 - y) = y(y2 - 1) = 2 × (4 - 1) = 6 (MULTIPLE of 6)When y = 3⇒ (y3 - y) = y(y2 - 1) = 3 × (9 - 1) = 24 (Multiple of 6)So, 4 is correct option.