None of the above.
First off, resolution and megapixels are the same thing.
Secondly, a 16-year-old who wants to really try photography is old enough for an interchangeable lens camera. So therefore, the zoom is irrelevant, since you can always change lenses.
Anyway, the biggest issues when choosing a camera and lens are not zoo or resolution: they are sensor size and lens aperture.
The majority of point and shoot cameras are at about the same quality level as a good smart phone camera.
I'd go with an interchangeable lens system -- either an entry level dslr like the Canon t5, Nikon D3300, Sony a58, or a mirrorless like the Samsung NX, Sony a5100, etc.