The circumference \( C \) of a circle can be calculated using the formula:
\[ C = \pi \times d \]
where \( d \) is the diameter.
In this case, the diameter \( d \) is 4 feet.
\[ C = \pi \times 4 \]
Using \( \pi \approx 3.14 \):
\[ C \approx 3.14 \times 4 = 12.56 \text{ feet} \]
So, the best estimation for the circumference from the options provided would be 13 feet.