Quy đồng mẫu thức các phân thức

Câu hỏi: Quy đồng mẫu thức các phân thức $\frac{\text{1}}{{\text{x}}^{\text{3}}+\text{1}}\text{;}\frac{\text{2}}{\text{3x}+\text{3}}\text{;}\frac{\text{x}}{{\text{2x}}^{\text{2}}-\text{2x}+\text{2}}$  ta được các phân thức lần lượt là?

A. $\frac{\text{1}}{{\text{x}}^{\text{3}}+\text{1}}\text{;}\frac{{\text{x}}^{\text{2}}-\text{x}+\text{1}}{{\text{3(x}}^{\text{3}}+\text{1)}}\text{;}\frac{{\text{x}}^{\text{2}}+\text{x}}{{\text{2(x}}^{\text{3}}+\text{1)}}$

B. $\frac{\text{1}}{{\text{6(x}}^{\text{3}}+\text{1)}}\text{;}\frac{{\text{x}}^{\text{2}}-\text{x}+\text{1}}{{\text{3(x}}^{\text{3}}+\text{1)}}\text{;}\frac{{\text{3x}}^{\text{2}}+\text{3x}}{{\text{6(x}}^{\text{3}}+\text{1)}}$

C. $\frac{\text{6}}{{\text{6(x}}^{\text{3}}+\text{1)}}\text{;}\frac{{\text{4x}}^{\text{2}}-\text{4x}+\text{4}}{{\text{6(x}}^{\text{3}}+\text{1)}}\text{;}\frac{{\text{3x}}^{\text{2}}+\text{3x}}{{\text{6(x}}^{\text{3}}+\text{1)}}$

D. $\frac{{\text{3x}}^{\text{2}}+\text{3x}}{{\text{6(x}}^{\text{3}}+\text{1)}}\text{;}\frac{{\text{4x}}^{\text{2}}-\text{4x}+\text{4}}{{\text{6(x}}^{\text{3}}+\text{1)}}\text{;}\frac{\text{6}}{{\text{6(x}}^{\text{3}}+\text{1)}}$