To find the length of the model of Paul's car, we need to calculate \( \frac{1}{6} \) of the actual length of the car.
The actual length of the car is 18 feet. So we can calculate the length of the model as follows:
\[ \text{Length of the model} = \frac{1}{6} \times 18 \text{ feet} = 3 \text{ feet} \]
Therefore, the length of the model is 3 feet.
The correct answer is:
B. 3 feet