In the passage "human problems" or "world problems" refers mainly to ______.

A．every American would buy alcohol illegally
B．all criminal activities would cease
C．patrols of the Canadian border would halt the sale of alcohol
D．the social threat from drunkenness would decline

A．lived in fear of the law
B．were willing to risk arrest for the pleasure of liquor
C．recklessly endangered their communities
D．were respectful of the legal sanctions placed on them