If the imaginary part of $\;\large\frac{2z+1}{iz+1}\;$ is $-2$ , then show that the locus of the point representing $z$ in the argand plane is a straight line .

Question

$(a)\;x+2y-2=0\qquad(b)\;2x+y+1=0\qquad(c)\;2x-2y+1=0\qquad(d)\;x=0$