Cho ba vectơ vecto a, vecto b, vecto c không đồng phẳng. Trong các khẳng định sau

A. Các vectơ $\overrightarrow{\mathrm{x}}=\overrightarrow{\mathrm{a}}+\overrightarrow{\mathrm{b}}+2\overrightarrow{\mathrm{c}};$$\overrightarrow{\mathrm{y}}=2\overrightarrow{\mathrm{a}}-3\overrightarrow{\mathrm{b}}-6\overrightarrow{\mathrm{c}};$$\overrightarrow{\mathrm{z}}=-\overrightarrow{\mathrm{a}}+3\overrightarrow{\mathrm{b}}+6\overrightarrow{\mathrm{c}}$ đồng phẳng.

B. Các vectơ $\overrightarrow{\mathrm{x}}=\overrightarrow{\mathrm{a}}-2\overrightarrow{\mathrm{b}}+4\overrightarrow{\mathrm{c}};$$\overrightarrow{\mathrm{y}}=3\overrightarrow{\mathrm{a}}-3\overrightarrow{\mathrm{b}}+2\overrightarrow{\mathrm{c}};$$\overrightarrow{\mathrm{z}}=2\overrightarrow{\mathrm{a}}-3\overrightarrow{\mathrm{b}}-3\overrightarrow{\mathrm{c}}$ đồng phẳng.

C. Các vectơ $\overrightarrow{\mathrm{x}}=\overrightarrow{\mathrm{a}}+\overrightarrow{\mathrm{b}}+\overrightarrow{\mathrm{c}};$$\overrightarrow{\mathrm{y}}=2\overrightarrow{\mathrm{a}}-3\overrightarrow{\mathrm{b}}+\overrightarrow{\mathrm{c}};$$\overrightarrow{\mathrm{z}}=-\overrightarrow{\mathrm{a}}+3\overrightarrow{\mathrm{b}}+3\overrightarrow{\mathrm{c}}$ đồng phẳng.

D. Các vectơ $\overrightarrow{\mathrm{x}}=\overrightarrow{\mathrm{a}}+\overrightarrow{\mathrm{b}}-\overrightarrow{\mathrm{c}};$$\overrightarrow{\mathrm{y}}=2\overrightarrow{\mathrm{a}}-\overrightarrow{\mathrm{b}}+3\overrightarrow{\mathrm{c}};$$\overrightarrow{\mathrm{z}}=-\overrightarrow{\mathrm{a}}-\overrightarrow{\mathrm{b}}+2\overrightarrow{\mathrm{c}}$ đồng phẳng.