If the discriminant of a quadratic is 0 then it means that the quadratic has two non-distinct roots or simply 1 real root. Thus the answer would be OPTION B
So an example would be 9x² + 12x + 4 = 0 in the form ax² + bx + c
the discriminant would be b² - 4ac = (12²) - 4(9)(4)
= 0
Now to solve to prove true
9x² + 12x + 4 = 9x² + 6x + 6x + 4 = 0
⇒ 9x² + 6x + 6x + 4 = 0
by factorising
3x(3x + 2) + 2(3x + 2)= 0
9x² + 6x + 6x + 4 = (3x + 2)²
which means it only has one root at x= 2/3
