In 2014, the birthrate in Costa Rica was 15 per 1000 people. In the same year, the death rate in Costa Rica was 5 per 1000 people. What was Costa Rica's approximate growth rate in 2014?
A. An increase of 20 per 1000 people
B. An increase of 10 per 1000 people
C. A decrease of 3 per 1000 people
D. An increase of 75 per 1000 people