Morning
Of the cameras listed, I think the Nikon is the way to go.
I like it above the others because it has the shortest zoom....yup shortest. Very long zooms can be difficult to handle.
The shorter zoom also keeps lens distortion to a minimum, and this is helped in the Nikon alone by having a built in lens correction feature.
The zoom has a focal length range of 27-486mm (slr equivalent) which is more than enough for anybody, and a 10 MPixel sensor......not as much as some of the others, but again more than enough for printing anything up to A3.
It also has full manual control of exposure as well as the usual auto options.
The Olympus is not for me.....no manual control. However good everything else is, that for me is a huge no-no........however, it may suit you and your needs.
The Pentax has a x24 zoom..............26-624mm.....overkill and difficult to handle...money wasted.
The Canon is a good camera with a zoom just a tad longer than the Nikon and the same 10 Mpixel sensor......but let down a wee bit for me by having a minimum iso rating of 80 rather than the 64 of the Nikon.
I would suggest a look at the Canon and Nikon......into the shop and get your hands on them and see how they fit.