c++: program settings - boost.PropertyTree or boost.program_options?

Question

I was looking for a solution to store program settings or options or configuration in C++. These could be settings that are exposed in a GUI and need to be saved between runs of my code.

In my search I came across boost.PropertyTree which seemed to be a good choice. I know boost is well respected code so I'm comfortable using it and so I started developing using this. Then I come across boost.program_options which seems to allow you to do the same thing but also looks more specialized for the specific use-case of program settings.

Now I'm wondering which is the most appropriate for the job? (or is there a 3rd option that is better than both)

EDIT: fyi this is for a plugin so it will not use command line options (as in, it's not even possible).

UPDATE

I ended up sticking with boost.PropertyTree. I needed to be able to save changed options back to the INI, and I didn't see a way of doing that with boost.program_options.