Which of the Following Is True Regarding Illness Anxiety Disorder

Which of the following is true regarding illness anxiety disorder (IAD) :

A) Many similarities have been noted between illness anxiety disorder and OCD.
B) The constant worrying and reassurance-seeking has a negative impact on interpersonal relationships.
C) Individuals with IAD often check their bodies for signs and symptoms of a disease/illness as well as researching illnesses on the internet.
D) All of the above.