To rationalize the denominator of the expression $\frac{1}{\sqrt[3]{7} - \sqrt[3]{4}}$, which factor should be multiplied to the numerator and denominator?

$\sqrt[3]{49} + \sqrt[3]{28} + \sqrt[3]{16}$

$\sqrt[3]{49} - \sqrt[3]{28} + \sqrt[3]{16}$

Which expression is equivalent to $\frac{z}{\sqrt[3]{z} + 1}$ after rationalizing the denominator?

$\frac{z(\sqrt[3]{z^2} - \sqrt[3]{z} + 1)}{z - 1}$

$\frac{z(\sqrt[3]{z} - 1)}{z - 1}$

$\frac{z(\sqrt[3]{z^2} - \sqrt[3]{z} + 1)}{z + 1}$

$\frac{z(\sqrt[3]{z^2} + \sqrt[3]{z} + 1)}{z + 1}$