Tell a bit of your personal history and story that has led you to care, some incident that opened up your eyes, or a moment of recognition. Stories like these really help people understand where you're coming from, especially if the story is relatable. It seems like the answer to this question should be obvious, but most people can answer this question much better after reflecting and writing for a bit.
A good way to end this question is to present a very short anecdote or statistic that leads to a question: “Entry level corporate jobs begin split evenly between men and women. By senior level it's 20% women and 80% men. For women of color it goes from 17% entry level to 3%. The question is: what causes this?”