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put this solution on YOUR website!Let

be the discriminant, i.e.

.
If

, then the roots are a conjugate pair of complex numbers of the form

.
If

, the roots are real and equal. (Also described as a single root with a multiplicity of 2)
If

, the roots are real and unequal.
Note that choice A is never possible, and choice B only occurs when

in

equals 0 so that the complex roots become

.