McKenna Had an Unplanned Pregnancy When She Was 19 Years

McKenna had an unplanned pregnancy when she was 19 years old. Following her pregnancy, McKenna started taking a birth control pill each day to prevent another pregnancy. In this case,

A) preventing a pregnancy acts as a positive reinforcer for taking birth control pills.
B) taking birth control pills acts as a negative reinforcer for preventing a pregnancy.
C) taking birth control pills acts as a positive reinforcer for preventing a pregnancy.
D) preventing a pregnancy acts as a negative reinforcer for taking birth control pills.