An example of moral hazard is​

A) ​people drive as carefully in icy conditions with antilock brakes as without
B) people drive as safely with more airbags as without
C) football players avoid 'spearing' with their heads even with safer helmets
D) ​people fail to read the medicine warnings more often when self-medicating versus with a doctor's prescription         

Competition is not necessarily diminished solely as a result of market concentration.