What Is the Difference Between Random Selection and Nonrandom Selection

What is the difference between random selection and nonrandom selection?

A) Random selection ensures that there is a large number of people selected, but nonrandom selection does not.
B) Nonrandom selection ensures that each person in the sample has the same likelihood of being chosen, while random selection does not.
C) Random selection is more regionally diverse than nonrandom sampling.
D) Random selection ensures that each person in the population has the same likelihood of being chosen, while nonrandom selection does not.