PbO2
You have to take the mass of lead in the problem, and divide by the molar mass.
When you do the same with oxygen, you get a number about twice as large as when you divide the mass of lead by the molar mass of lead. This means that the simplest formula would be PbO2
I think the correct answer would be B. The process of electroplating uses a direct current in order to give a cheap metal the apperance and resistance of a more expensive metal by coating it with a certain metal. The current reduces the dissolved metal ions to form a thin coating on a surface.