Read the paragraph and answer the following questions.
Paragraph : Two stars P and Q each having mass M constitute a binary system. The stars revolves in circular orbits about their centre of mass under the effect of mutual gravitational force of attraction. The radius of orbit of star P is R. The dimensions of stars are negligible as compared to the separation between the stars.
The orbital speed of star Q is :

Options

A. `sqrt((GM)/(R ))`
B. `sqrt((2GM)/(R ))`
C. `sqrt((GM)/(2R))`
D. `sqrt((GM)/(4R))`

Answer

D