A spherically symmetric gravitational system of particles has a mass density $$\rho = \begin{cases}\rho_0 & for & r \leq R\\0 & for & r > R\end{cases}$$ where $$\rho_0$$ is a constant. A test mass can undergo circular motion underthe influence of the gravitational field of particles. Its speed V as a function of distance $$r(0 < r < \infty)$$ from the center of the system is represented by

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B

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D