Which statement best describes why there is no real solution to the quadratic equation y = x2 - 6x + 13?
the value of (-6)2 - 4 • 1 • 13 is a perfect square.
the value of (-6)2 - 4 • 1 • 13 is equal to zero.
the value of (-6)2 - 4 • 1 • 13 is negative.
the value of (-6)2 - 4 • 1 • 13 is positive