Well, it's actually none of those.
The Temeraire series takes place in an alternate timeline, during the late 18th century. The 'alternate history' part means that this world is like ours was, but with a small, almost insignificant change: there are dragons. These dragons are, for the most part, tamed by humans and used in warfare, resulting in an elite military division in most countries that specialize in dragon warfare. There is, however, a slight problem for those who want to utilize dragons in warfare: they are just as intelligent as people (or even more so). The story follows two characters, although for the most part it is from the viewpoint of the first: William Lawrence, a Navy officer turned dragon captain, and the dragon Temeraire, who Lawrence serves with. It really is a great series, and if you have any intrest at all in dragons (which, I assume, is why you are here) I suggest you pick up at least the first of the five, soon (hopefully) to be six, books.