A double star consists of two stars having masses m and 2m. The distance between their centers is equal to r. They revolve under their mutual gravitational attraction. Which is/are correct? a) The force experienced by the star of mass m is Gm(2m) /r² b) The force experienced by the star of mass 2m is Gm(2m) /r² c) The force experienced by the star of mass m is Gm²/r² d) The force experienced by the star of mass 2m is 2Gm²/r²