Decide whether or not the equation below has a circle as its graph. If it does, give the center and the radius. If it does not, describe the graph.
81x ^2+81y^2-72x+72y - 32 = 0
choose the correct statement about the given equation and if necessary fill in the answer boxes within your choice.
a. The graph of the equation is a circle with center (Type an ordered pair. Use integers or fractions for any numbers in the expression) The radius of the circle is Type an integer or a simplified fraction) b. The graph of the equation is the point (Type an ordered pair. Use integers or fractions for any numbers in the expression) c. The graph of the equation is a line d. The graph is nonexistent.