Even Though Phobias May Interfere with an Individual's Functioning, Only

Even though phobias may interfere with an individual's functioning, only the most severe cases come for treatment.Why?

A) Affected people tend to arrange their life to avoid the phobic object or situation.
B) Less extreme phobias tend to fade over time without treatment.
C) The continuing shame and stigma surrounding mental disorders results in affected people avoiding treatment.
D) Most people with less severe cases tend to believe their fears are normal and reasonable.