Answer:
B. Lines of symmetry: 1
Step-by-step explanation:
I calculated it logically
For this case we must find the perimeter of the fence, in a circular way, knowing that the perimeter of a circle is given by:

Where "r" represents the radius of the circle, in this case 
Substituting in the perimeter equation we have:

Rationalizing we have:

Taking out common factor
:

Answer:

Option C