The iteration step in order to solve for the cube roots of a given number N using the Newton-Raphson's method is

A. $${{\text{x}}_{{\text{k}} + 1}} = {{\text{x}}_{\text{k}}} + \frac{1}{3}\left( {{\text{N}} - {\text{x}}_{\text{k}}^3} \right)$$

B. $${{\text{x}}_{{\text{k}} + 1}} = \frac{1}{3}\left( {2{{\text{x}}_{\text{k}}} + \frac{{\text{N}}}{{{\text{x}}_{\text{k}}^2}}} \right)$$

C. $${{\text{x}}_{{\text{k}} + 1}} = {{\text{x}}_{\text{k}}} - \frac{1}{3}\left( {{\text{N}} - {\text{x}}_{\text{k}}^3} \right)$$

D. $${{\text{x}}_{{\text{k}} + 1}} = \frac{1}{3}\left( {2{{\text{x}}_{\text{k}}} - \frac{{\text{N}}}{{{\text{x}}_{\text{k}}^2}}} \right)$$

Answer: Option B