How to use OnItemSelect += (sender, item, index) => twice?

OneMinuteYT

so i am trying to make a modmenu but i can only use a "if" statement for on thing

vehicleoptions.OnItemSelect += (sender, item, index) =>

     {
         if (item == adder)
         {
             Vehicle car = World.CreateVehicle("ADDER", Game.Player.Character.Position);
             Game.Player.Character.SetIntoVehicle(car, VehicleSeat.Driver);
         }

but if i want to use it with a other item while this enabled i will get an error:

A local or parameter named 'index' cannot be declared in this scope because that name is used in an enclosing local scope to define a local or parameter

it also says the exact same about sender and item does anyone know how to fix this?

i also tried the "else" and end method but dind't work