Correct ans : B. Please give the solution in detail.

On applying Work-Energy theorem which states that net work done by all conservative , non-conservative, internal, or external forces is equal to net change in kinetic energy.The forces present here are:Gravity force: mgElectrostatic force: EqTension Force of the rod: TNet Work Done= work done by gravity + work done by electrostatic force + tension forceWork done = (Force) * (Displacement of particle in the direction of force ) Therefore, Work done by tension force is zero. W(net) = Change in KE=> mgh + Eqx + (work done tension) = final KE - Initial KE=> mgh + Eqx = 1/2*(m)*v*v - 1/2*(m)*u*uwhere x=horixontal displacement of m along Eh=vertical displacement of m along gravityv= magnitude of final velocityu=magnitude of initial velocityLet w=angular velocity at final position then w= v/lx=l*sin 45h=l - l*cos 45E= mg/q u=0put the value and you will get your answer B.