Solve the equation : $\;x^{2}+3x+9=0\;$

Question

$(a)\;\large\frac{-5 \pm3 \sqrt{3}i}{2}\qquad(b)\;\large\frac{3 \pm3 \sqrt{3}i}{2}\qquad(c)\;\large\frac{-3 \pm 3 \sqrt{3}i}{2}\qquad(d)\;0$