In this context, the terms 'Britain', 'British Isles' or 'British' include everyone from which places?

Okay, let's talk about what "Britain" and the "British Isles" actually mean. Geographically, the British Isles is a group of islands off the northwest coast of Europe. Now, the key thing to remember for the test is that politically, "Britain" refers specifically to the United Kingdom. The UK is a sovereign state composed of four countries: England, Scotland, Wales, and Northern Ireland. So, when the test asks who is included when using the terms "Britain," "British Isles," or "British," it's referring to the people from those four countries. It's easy to get confused because the "British Isles" geographically includes the Republic of Ireland, but politically, the Republic of Ireland is a separate, independent country. The Isle of Man and Channel Islands are also geographically part of the British Isles, but they're self-governing Crown Dependencies and not part of the UK. So, while they have close ties to the UK, their people aren't automatically considered "British" in the same way.