Select the quadratic equation that has no real solution.
x ² + 2 x + 3 = 0
x ² - 7 x + 5 = 0
- x ² + 3 x + 4 = 0
x ² + 4 x + 4 = 0
x ² + 2 x + 3 = 0
x ² - 7 x + 5 = 0
x ² + 4 x + 4 = 0