Air Temperature Decreases by About 0

Air temperature decreases by about 0.8°C for every additional degree north or south of the equator.Washington,D.C. ,is at 38.5°N,and its average temperature is 12.0°C.Atlanta,Georgia,is at 33.5°N.Assuming that the only factor affecting temperature differences between Washington and Atlanta is latitude,what is the expected annual average temperature in Atlanta?

A) 4.0°C
B) 16.0°C
C) 17.0°C
D) 18.2°C
E) 20.6°C