From the problem, we have the inequality :

Divide both sides by 8 :

The solution is d is greater than or equal to 5.
Frankie and Nick's solution starts from x = -5 and the direction is to right.
Note that if the inequality symbols are < or >, the endpoint must be a non-shaded circle, otherwise it is a shaded circle
Since the inequality symbol is ≥, the endpoint must be a shaded circle.
ANSWER :
Frankie's solution is correct because the endpoint is a shaded circle.
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