Final answer:
Long-term use of Oral Contraceptive Pills (OCPs) has been associated with a reduced risk of ovarian cancer. This protective effect grows with the duration of OCP use, and it is theorized that the fewer ovulations due to OCP use may be protective against ovarian cancer.
Step-by-step explanation:
The subject of this question is the association between long-term Oral Contraceptive Pills (OCPs) use and ovarian cancer. When considering the options protective, risk, no association, and variable association, numerous studies have provided evidence that long-term use of OCPs is associated with a reduced risk of ovarian cancer. This protective effect seems to intensify with longer durations of OCP use.
It is theorized that the reduction in the total number of ovulations, due to the suppression of ovulation by OCPs, might be the mechanism that reduces the risk for developing this cancer. Thus, the correct answer to the question, "Long-term OCPs are protective or a risk for Ovarian Cancer?" is a. Protective.