If $\overrightarrow{\mathrm{a}},\overrightarrow{\mathrm{b}},\overrightarrow{\mathrm{c}}$  any three non-coplanar vectors, then the equation $[\overrightarrow{\mathrm{b}}\times \overrightarrow{\mathrm{c}}\overrightarrow{\mathrm{c}}\times \overrightarrow{\mathrm{a}}\overrightarrow{\mathrm{a}}\times \overrightarrow{\mathrm{b}}]{\mathrm{x}}^2+[\overrightarrow{\mathrm{a}}+\overrightarrow{\mathrm{b}}\overrightarrow{\mathrm{b}}+\overrightarrow{\mathrm{c}}\overrightarrow{\mathrm{c}}+\overrightarrow{\mathrm{a}}]\mathrm{x}+1+[\overrightarrow{\mathrm{b}}-\overrightarrow{\mathrm{c}}\overrightarrow{\mathrm{c}}-\overrightarrow{\mathrm{a}}\overrightarrow{\mathrm{a}}-\overrightarrow{\mathrm{b}}]=0$ has roots

• A

  real and distinct

• B

  real

• C

  equal

• D

  imaginary