c
\(\hat n = \frac{{\overrightarrow A \, \times \overrightarrow B }}{{|\overrightarrow A \, \times \overrightarrow B |}} = \frac{{8\hat i - 8\hat j - 8\hat k}}{{8\sqrt 3 }} = \frac{1}{{\sqrt 3 }}(\hat i - \hat j - \hat k)\)
\(\hat n = \pm \frac{1}{{\sqrt 3 }}(\hat i - \hat j - \hat k)\)