The best response to the question about how the author uses the last paragraph to develop and refine the central idea is:
The author’s central idea is that the lack of representation of people with disabilities leaves science worse off. The last paragraph gives reasons that people with disabilities are needed in science—because they have tremendous innovative capacities.
This choice accurately captures the central message of the excerpt and explains how the last paragraph reinforces that message by highlighting the valuable innovations people with disabilities can bring to scientific fields.