A committee studied the populations of two towns at the beginning of each year. The population of town 1 was 18,038 in 2007 and 21,974 in 2010. The population of town 2 was 11,200 in 2007 and 15,735 in 2010. If the populations of both towns grew exponentially, at the beginning of which year were the populations about the same? A. 2015 B. 2016 C. 2017 D. 2018