What Is a Good Method to Extinguish an Avoidance Response,and

What is a good method to extinguish an avoidance response,and also to treat phobia?​

A) Present the feared stimulus and prevent the avoidance response.
B) ​Prevent any contact with the feared stimulus for at least a week.
C) ​Provide positive reinforcement for the avoidance response, on an interval schedule.
D) ​Provide positive reinforcement for the avoidance response, on a ratio schedule.