What will happen by 2100, according to a new study?

参考解析：

细节理解题。根据文章第一段第一句“Rising temperatures and overfishing in the pristine waters around the Antarctic could see king penguin populations pushed to the brink of extinction by the end of the century…”以及第三段首句“Unless current greenhouse gas emissions drop, 70 percent of king penguins—1.1 million breeding pairs—will be forced to relocate their breeding grounds, or face extinction by 2100”可知“南极周围原始（未受污染）水域的气温升高和过度捕捞可能会使帝王企鹅种群在本世纪末濒临灭绝”。其余三项原文未提及。故选A。