Identify each variable as categorical or quantitative:

(a) Level of education (high school, bachelor’s, master’s).

(b) Number of times married.

(c) Hair color.

(d) Preferred type of exercise.

(e) Type of residence (rented apartment, owned apartment, rented house, owned house).

(f) Number of household members.

(g) Height.

(h) Field of study (humanities, social sciences, natural sciences).

(i) Number of close friends.