The passage states, "For a long while I could not utter a single word. Then, after what seemed like eternity, I sighed and told my husband to go to Dr. Samjohn and personally apologise on my behalf. I could not see myself going back to the school to face my HOD after my inexcusable behaviour." The narrator mentions that she was silent for a long time after her husband made a revelation, and later she sent him to apologize to Dr. Samjohn. The passage then says, "But then, he was right. Nothing ever happened. It took a while for me to wrestle with my conscience and convince myself that indeed nothing happened." This suggests that the narrator's husband revealed something that caused her to feel guilty, but ultimately she realized that nothing actually happened. Based on this information, we can infer that the revelation occurred 20 years ago, as stated in option C