【正确答案】 A

【答案解析】原文：For the first time ever, scientists have recorded the heart rate of the world’s largest creature: the blue whale. To get this reading, they attached an electrocardiogram device to the body of a whale. They found that the mammal’s heart rate can slow to just two beats a minute as the animal searches for food below the surface of the ocean. The highest heart rate they recorded was 37 beats a minute after the whale returned to the surface for air.题目问联合国科学报告中传达的信息是什么。新闻最后提到“The report notes that the effects of climate change are already making food more costly and less nutritious and are worsening food shortages”，即联合国科学报告指出，气候变化的影响已经使粮食成本更高,营养更差，而且正在加剧粮食短缺,故选A。