2.In quadratic equation ax2 + bx + c = 0, if discriminant is D= b2 - 4ac, then roots of the quadratic equation are

(choose the correct alternative)

(1) Real and distinct, if D > 0

(2) Real and equal (i.e., repeated roots), if D = 0.

(3) Non-real (i.e. imaginary), if D< 0

(4) All of the above are correct​