【正确答案】 A

【答案解析】原文：Researchers are sailing to a distant part of Antarctica. So they can better understand how much and how fast seas could rise because of global warming. The area which is where the Thwaites glacier is located is sometimes called the place in the world that’s the hardest to get to. 32 scientists are starting a more than 2 month-trip aboard an American research ship. Their goal is to study the area where the large but melting Thwaites glacier faces the amounts in sea.根据新闻可知，病毒的最新变种奥密克戎几周前才出现，但科学家们知道，这不会是最后一次，奥密克戎“拉响了火警”。也就是说，病毒变异体会持续出现，故选A。