Which of the Following Statements About Tics Is True

Which of the following statements about tics is true?

A) Vocal tics (e.g., clicks, grunts) are more common than motor tics.
B) Approximately 50% of youth with autism have at least one tic
C) Tourette's syndrome is defined by the presence of coprolalia, that is, the involuntary utterance of obscenities.
D) Tics and Obsessive-Compulsive Disorder (OCD) may have similar underlying causes.