You are given the following estimation results of the effect of education on number of children. Data are for women in Botswana during 1988 and include information on number of children (children, years of education educ, age, and additional individual characteristics: if they have electricity - electric, television tv, a bicycle - bicycle), and whether they live in an urban area, urban. What is the marginal effect of age in column 1 ? Code all that apply. Table 2: ULS estimates. Uutcome:number of children. a. The number of children increases with age in the age range in which a woman is fertile b. 0.3320.003 age c. 0.332 d. 0.33220.003 age