Use the map below, which shows the percentage of the population that is over 65 years old in European nations, to answer the following question: Use the map below, which shows the percentage of the population that is over 65 years old in European nations, to answer the following question:

A 2010 map of the European countries showing the percentage of the population that is over 65 years old in each country, by the following ranges: less than 12 percent Turkey, Cyprus, Albania, Moldova, and Macedonia, 12 to 14 percent Russia, Poland, Slovakia, Iceland, Ireland, Bulgaria, and Montenegro, 14 to 16 percent Norway, Netherlands, Czech Republic, Hungary, Ukraine, Belarus, Romania, Serbia, and Bosnia and Herzegovina, 16 to 18 percent Portugal, United Kingdom, France, Belgium , Luxemburg, Switzerland, Slovenia, Croatia, Finland, Estonia, Latvia, Lithuania, 18 to 20 percent Spain, Austria, Sweden, and Denmark, greater than 20 percent Germany, Italy, and Greece.

According to the map, which statement is correct? (5 points)

a The population of southern Europe is growing faster than that of northern Europe.

b The average age of the population in Western Europe is higher than in Eastern Europe.

c Nations that are historically younger also tend to have younger populations.

d Immigration has lowered the age of the populations of some European nations.