Answer:
Option A:

Explanation:
Circumference of a circle is given by the formula
C = πd
where d = diameter of the circle
Given
C = 56.52
d= 18 feet
56.52= 18π

This is option A
If you were every in doubt about the correct answer, all you have to know is that the value of π = 3.14
C and D have ratios less than 1
B has a ratio of approx 6
A has a ratio close to 3