The condition that the roots of $x^3-bx^2+cx-d=0$ are in geometric progression is :

$\begin {array} {1 1} (1)\;c^3=b^3d & \quad (2)\;c^2=b^2d \\ (3)\;c=bd^3 & \quad (4)\;c=bd^2 \end {array}$

$(1)\;c^3=b^3d$