The property of inequality that justifies the steps shown in the solution process is the Multiplication Property of Inequality.
In the process, both sides of the inequality \( \frac{4}{3}d ≥ -20 \) were multiplied by \( \frac{3}{4} \), which is a positive number. According to the Multiplication Property of Inequality, when you multiply or divide both sides of an inequality by a positive number, the direction of the inequality does not change.
Thus, the correct response is:
Multiplication Property of Inequality.