What Was One Effective Tool Used by the Anti-Abortionists to Cut

What was one effective tool used by the anti-abortionists to cut down the number of abortions in the United States?

A) Pamphlets left in public places like hospital parking lots and outside supermarkets
B) Visits to public high schools to give talks on the consequences of early sexual activity
C) Demonstrations and violence against abortion clinics and medical providers
D) Passage of a constitutional amendment banning abortion