Someone me quick

which is true of early labor unions?

a. companies hired private guards to attack strikers or union organizers.

b. labor union members openly recruited fellow workers and defied management.

c. laws guaranteed the rights of laborers to strike for better pay and conditions.

d. most early labor unions were successful in getting better pay.

Donald is studying the eating habits of all students attending his school. he samples the population by dividing the students into groups by grade level and randomly selecting a proportionate number of students from each group. he then collects data from the sample. which type of sampling is used? select the correct answer below: systematic sampling convenience sampling stratified sampling cluster sampling