What is the standard form of this equation of a circle?
x2 + y2 + 14x − 4y − 28 = 0



(x + 2)2 + (y − 7)2 = 81


(x + 7)2 + (y − 2)2 = 81


(x + 5)2 + (y − 3)2 = 49


(x + 4)2 + (y + 5)2 = 25