Management at a Post Office Is Curious About Its Services

Management at a post office is curious about its services in one small town.Every address within that town,including business and residential,is mailed a survey inquiring about the post office's quality of service.The post office does receive a respectable 25% response rate to the survey.However,what,if any,is the most noticeable bias for this survey?

A) Voluntary response bias
B) Nonresponse bias
C) Response bias
D) Undercoverage of the population
E) There does not seem to be any bias.