To determine the inequality Liang can use to find \( h \), the number of hours she should walk to meet or exceed her goal of 18 miles at a rate of 4 miles per hour, we can set up the equation as follows:
The total distance walked can be calculated as: \[ \text{Distance} = \text{Rate} \times \text{Time} \]
In this case, the distance Liang wants to walk is at least 18 miles, and she walks at a rate of 4 miles per hour. Therefore, we can express this relationship with the following inequality:
\[ 4h \geq 18 \]
So, the correct inequality that Liang can use is:
\[ h \geq \frac{18}{4} \]
Simplifying this gives:
\[ h \geq 4.5 \]
If this was part of a multiple-choice question with options A, B, C, and D, we would need to see those choices to identify the correct option representative of this inequality. However, the mathematical formulation is \( 4h \geq 18 \).