Consider the following regression model: wage=1+1male+imalexedu+2edu+ui where wage is the hourly wage measured in dollars; male is a dummy variable for males; edu is the years of education; malexedu is the interaction of male and edu variables. The parameter estimates for parameters are 1=1;2=2;2=0.2;1=1. What is the predicted marginal effect of years of education for males? a. 1.2 b. 2.2 C. 0.8 d. 1