13) D

We need to use the inequalities given in the options to solve this question.

x² ≥ 8 – 2x

Rearranging,
x² + 2x – 8 ≥ 0

Factorising (x + 2x – 8),
x² – 2x + 4x – 8
x(x – 2) + 4(x – 2)
So we have, (x – 2) (x + 4) ≥ 0
Writing them down individually,

x – 2 ≥ 0
x + 4 ≤ 0

Rearranging,
x ≥ 2
x ≤ -4

So the answer is D.