BRAINLIEST IF CORRECT
Generating random samples.

Answer:
1st and 3rd answer
Step-by-step explanation:
1st answer - Having a sample that is not random does not allow you to generalize the results of the experiment/study to the population because it is not representative of the population in the first place.
3rd answer - The definition of a random sample is that each member of the population has an equal chance of being selected.