Investigate past climate and atmospheric changes
Answer: d. It is physically separate from the rest of the United Kingdom, a multinational state.
Explanation:
Northern Island is one of the constituent countries of the United Kingdom and from the map one can see that it is physically separated from the rest of the U.K. .
The entire island where the Irish countries are situated used to be part of the U.K. up until 1922 when the current Republic of Ireland seceded from the U.K. after the Irish War of Independence.
A rift zone sometimes occurs in some volcanoes, more so in the shield volcanoes. It is made up of a linear series of fissures in the volcanic edifice. Lava can erupt from this, let us call it volcanic flank, instead of it's summit. Rift zones tend to extend for dozens of kilometers. Volcanoes have an elongated shape because of the repeated eruptions from these rift zones.
The answer is either C or D. I’m not sure but i’m closer to D. Hope this helped!