In Addition to the Time and Effort Involved, What Other

In addition to the time and effort involved, what other factor is cited by many experts when arguing for the rationality of not voting?

A) the small chance any one person's vote will be decisive in any election
B) the divisiveness of many political campaigns today
C) the level of "noise" in the message of politicians who seek office
D) the overall level of distrust and the potential for abusing the public interest