Correct Answer - A::B::C
`r=a/2 sec 30^(@)=a/(sqrt(3))`
`F=(Gmm)/(a^(2))`
`F_(net)=sqrt(3)F=((Gmm)/(a^(2))) (sqrt(3))`
This will provided the necassary centripetal force.
`:. (mv^(2))/r=(sqrt(3)Gm^(2))`
`T=(2pir)/v=(2pi(a//sqrt(3)))/(sqrt(Gm//a))=2pisqrt((a^(3))/(3Gm))`