I think there are two parts to this question.
First of all, it depends on Compiler. Compiler in turns usually depends on the architecture, processor, development environment etc because it takes them into account. So you may say it's a combination of all.
But I would NOT say that. I would say, Compiler, since on the same machine you may have different sizes of POD and built-in types, if you use different compilers. Also note that your source code is input to the compiler, so it's the compiler which makes final decision of the sizes of POD and built-in types.
However, it's also true that this decision is influenced by the underlying architecture of the target machine. After all, the real useful compiler has to emit efficient code that eventually runs on the machine you target.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.