Why are scientists drilling into the Antarctic ice? to build permanent settlements to learn about the Earth's ancient environment to extract fresh water to find sources of oil

Scientists are drilling into the Antarctic ice in order to study ice cores, as this can give a cue to earth's ancient climate and environment. This is because airborne relics of Earth's earlier climate can end up trapped in glacial ice for eons. This makes the second option, " to learn about the Earth’s ancient environment " the right answer.