The discriminant of a quadratic equation \( ax^2 + bx + c = 0 \) is given by: \[ \Delta = b^2 - 4ac \] For the roots to be real and distinct, the discriminant must be positive. Thus, the condition for real and distinct roots is: \[ \Delta = b^2 - 4ac>0 \] Therefore, the correct answer is: \[ \boxed{(A) \, b^2 - 4ac>0} \]