Suppose that unemployment rate in Miami was 5% in 1979 and 9% in 1981. The unemployment rate in other US cities was 4% in 1979 and 7% in 1981. Assume you use these data and the difference-in-differences method to measure the impact of the arrival of Marielitos (in 1980) on the Miami labor market. In that case, you would conclude that:

a)Marielitos increased unemployment in Miami by 1 percentage point

b)Marielitos increased unemployment in Miami by 4 percentage points

c)Marielitos increased unemployment in Miami by 2 percentage points

d)Marielitos had no effect on unemployment in Miami

e)Marielitos increased unemployment in Miami by 3 percentage points