The correct answer is (c). The UNHCR reported that the number of refugees and migrants in Europe reached 2 million in 2015. This was a significant increase from the previous year, when the number was 1.5 million. The majority of the refugees and migrants came from Syria, Iraq, and Afghanistan. They were fleeing war, persecution, and poverty. Many of them made the dangerous journey across the Mediterranean Sea in search of a better life in Europe. The influx of refugees and migrants has put a strain on European countries, which are struggling to provide them with food, shelter, and medical care. It has also led to tensions between European countries, as they try to agree on how to deal with the crisis.
Option (a) is incorrect because the number of refugees and migrants in Europe reached 2 million in 2015, not 1 million.
Option (b) is incorrect because the number of refugees and migrants in Europe reached 2 million in 2015, not 1.5 million.
Option (d) is incorrect because the number of refugees and migrants in Europe reached 2 million in 2015, not 3 million.