Population is the total number of persons or things means in a Study as a matter of interest. n= Sample size. Sample is the subset of the population. Just try to explain it in a example: A researcher want to know.
He is too young to walk home alone to an apartment. He is too young to be home alone by himself. He spends too much time alone & could get into trouble, because at that age he does not have the life experiences to know right from wrong or good from evil. Something could happen to him from the time he gets out of school and when his mom finally gets home, and no one would even know about it. He has a poor diet & a poor roll model. He will have many health issues in his future. He may also feel isolated & alone.
I think its B. Has written cause if he wrote it then he can submit it to the editor
