Consider the model where the dependent variable is the number of children a woman has and the independent variable is a variable that measures the number of years the same woman studied. It can be said that the model intends to establish a certain relationship between fertility and the education of the mother. a) Comment on the type of factors that appear in the stochastic term. b) Determine if these factors are correlated with the level of education. c) Establish if the estimators that you would obtain from this estimation are unbiased and of variance minimum.