Which Statement Best Describes the Central Problem in Determining Whether

Which statement best describes the central problem in determining whether or not a sexual practice is abnormal?

A) The abnormal behavior usually does not threaten society, impair social or occupational functioning, or cause distress to the individual.
B) While the laws are usually clear about what is illegal, people are often unaware of the laws.
C) Acceptable, "normal" sexual practices differ between cultures and historical times.
D) The DSM-5 only lists sexual disorders that are illegal, not ones that are merely unusual or abnormal.