Concept:Brabantio’s rage is triggered by Othello’s secret marriage to Desdemona.Explanation:In the extract, Brabantio is disturbed because Desdemona has left his house without consent.This secret union is described as Othello’s elopement with Desdemona.It is this act that sparks Brabantio’s anger and the ensuing conflict.Answer:D. Othello’s elopement with Desdemona