Which of the following statements best characterizes the change in trends for refugees seeking entry to the US from 1999 to 2009?
a. The numbers of refugees from southern Europe decreased, while the numbers from Africa increased.
b. The numbers of refugees from Asia decreased, while the numbers from southern Europe increased.
c. The numbers of refugees from southern Europe and Africa both increased.
d. The numbers of refugees from southern Europe and Africa both decreased, while the numbers from Asia increased.