Which of the following is the pair of biofertilizers?

$A$ spherical solid ball of volume $V$ is made of a material of density $\rho_1$. It is falling through a liquid of density $\rho_2$ (where $\rho_2 < \rho_1$). Assume that the liquid applies a viscous force on the ball that is proportional to the square of its speed $v$,i.e.,$F_{viscous} = -kv^2$ (where $k > 0$). Then the terminal speed of the ball is:

If $\omega$ is a complex cube root of unity,then $(x+1)(x+\omega)(x-\omega-1)$ is equal to

The roots of the equation $x^3-14x^2+56x-64=0$ are in

If $x > 0$ and $x^y = e^{x-y}$,then $\frac{dy}{dx}$ is equal to

$A$ disc of radius $R$ is made to oscillate about a horizontal axis passing through its periphery. Its time period would be