To find the circumference of a circle, you can use the formula:
\[ C = \pi \times d \]
where \( C \) is the circumference and \( d \) is the diameter.
Given that the diameter \( d = 3.75 \) kilometers and using \( \pi \approx 3.14 \):
\[ C = 3.14 \times 3.75 \]
Now, performing the multiplication:
\[ C = 11.775 \]
Rounding to the hundredths place, the circumference is:
\[ C \approx 11.78 \text{ kilometers} \]
So, the circumference of the circle is approximately 11.78 kilometers.